avformat: use ff_alloc_extradata()

Signed-off-by: Paul B Mahol <onemda@gmail.com>

52 files changed, 83 insertions, 218 deletions

diff --git a/libavformat/adxdec.c b/libavformat/adxdec.c
index 38f09f4ca7..0a0436f184 100644
--- a/libavformat/adxdec.c
+++ b/libavformat/adxdec.c
@@ -78,8 +78,7 @@ static int adx_read_header(AVFormatContext *s)
     c->header_size = avio_rb16(s->pb) + 4;
     avio_seek(s->pb, -4, SEEK_CUR);
 
-    avctx->extradata = av_mallocz(c->header_size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!avctx->extradata)
+    if (ff_alloc_extradata(avctx, c->header_size))
         return AVERROR(ENOMEM);
     if (avio_read(s->pb, avctx->extradata, c->header_size) < c->header_size) {
         av_freep(&avctx->extradata);
diff --git a/libavformat/afc.c b/libavformat/afc.c
index 183a8e0030..8dbd232fc1 100644
--- a/libavformat/afc.c
+++ b/libavformat/afc.c
@@ -39,10 +39,8 @@ static int afc_read_header(AVFormatContext *s)
     st->codec->codec_id   = AV_CODEC_ID_ADPCM_AFC;
     st->codec->channels   = 2;
     st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
-    st->codec->extradata_size = 1;
 
-    st->codec->extradata = av_mallocz(1 + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, 1))
         return AVERROR(ENOMEM);
     st->codec->extradata[0] = 8 * st->codec->channels;
 
diff --git a/libavformat/aiffdec.c b/libavformat/aiffdec.c
index 851091e5cb..2883713253 100644
--- a/libavformat/aiffdec.c
+++ b/libavformat/aiffdec.c
@@ -276,10 +276,8 @@ static int aiff_read_header(AVFormatContext *s)
         case MKTAG('w', 'a', 'v', 'e'):
             if ((uint64_t)size > (1<<30))
                 return -1;
-            st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (!st->codec->extradata)
+            if (ff_alloc_extradata(st->codec, size))
                 return AVERROR(ENOMEM);
-            st->codec->extradata_size = size;
             avio_read(pb, st->codec->extradata, size);
             if (st->codec->codec_id == AV_CODEC_ID_QDM2 && size>=12*4 && !st->codec->block_align) {
                 st->codec->block_align = AV_RB32(st->codec->extradata+11*4);
diff --git a/libavformat/apc.c b/libavformat/apc.c
index bb28a628f7..08ae9351dc 100644
--- a/libavformat/apc.c
+++ b/libavformat/apc.c
@@ -23,6 +23,7 @@
 
 #include "libavutil/channel_layout.h"
 #include "avformat.h"
+#include "internal.h"
 
 static int apc_probe(AVProbeData *p)
 {
@@ -51,10 +52,7 @@ static int apc_read_header(AVFormatContext *s)
     avio_rl32(pb); /* number of samples */
     st->codec->sample_rate = avio_rl32(pb);
 
-    st->codec->extradata_size = 2 * 4;
-    st->codec->extradata = av_malloc(st->codec->extradata_size +
-                                     FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, 2 * 4))
         return AVERROR(ENOMEM);
 
     /* initial predictor values for adpcm decoder */
diff --git a/libavformat/ape.c b/libavformat/ape.c
index 7ed9dd813b..613a59d5f8 100644
--- a/libavformat/ape.c
+++ b/libavformat/ape.c
@@ -354,8 +354,8 @@ static int ape_read_header(AVFormatContext * s)
     st->duration  = total_blocks;
     avpriv_set_pts_info(st, 64, 1, ape->samplerate);
 
-    st->codec->extradata = av_malloc(APE_EXTRADATA_SIZE);
-    st->codec->extradata_size = APE_EXTRADATA_SIZE;
+    if (ff_alloc_extradata(st->codec, APE_EXTRADATA_SIZE))
+        return AVERROR(ENOMEM);
     AV_WL16(st->codec->extradata + 0, ape->fileversion);
     AV_WL16(st->codec->extradata + 2, ape->compressiontype);
     AV_WL16(st->codec->extradata + 4, ape->formatflags);
diff --git a/libavformat/apetag.c b/libavformat/apetag.c
index ab93736718..a376a0bc4a 100644
--- a/libavformat/apetag.c
+++ b/libavformat/apetag.c
@@ -88,14 +88,13 @@ static int ape_tag_read_field(AVFormatContext *s)
             st->attached_pic.stream_index = st->index;
             st->attached_pic.flags       |= AV_PKT_FLAG_KEY;
         } else {
-            st->codec->extradata = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (!st->codec->extradata)
+            if (ff_alloc_extradata(st->codec, size))
                 return AVERROR(ENOMEM);
             if (avio_read(pb, st->codec->extradata, size) != size) {
                 av_freep(&st->codec->extradata);
+                st->codec->extradata_size = 0;
                 return AVERROR(EIO);
             }
-            st->codec->extradata_size = size;
             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
         }
     } else {
diff --git a/libavformat/avidec.c b/libavformat/avidec.c
index 44ab9d9a3f..1a40e94c82 100644
--- a/libavformat/avidec.c
+++ b/libavformat/avidec.c
@@ -648,12 +648,8 @@ static int avi_read_header(AVFormatContext *s)
                             st->codec->extradata_size = esize - 10 * 4;
                         } else
                             st->codec->extradata_size =  size - 10 * 4;
-                        st->codec->extradata      = av_malloc(st->codec->extradata_size +
-                                                              FF_INPUT_BUFFER_PADDING_SIZE);
-                        if (!st->codec->extradata) {
-                            st->codec->extradata_size = 0;
+                        if (ff_alloc_extradata(st->codec, st->codec->extradata_size))
                             return AVERROR(ENOMEM);
-                        }
                         avio_read(pb,
                                   st->codec->extradata,
                                   st->codec->extradata_size);
@@ -781,12 +777,8 @@ static int avi_read_header(AVFormatContext *s)
                 st = s->streams[stream_index];
 
                 if (size<(1<<30)) {
-                    st->codec->extradata_size= size;
-                    st->codec->extradata= av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-                    if (!st->codec->extradata) {
-                        st->codec->extradata_size= 0;
+                    if (ff_alloc_extradata(st->codec, size))
                         return AVERROR(ENOMEM);
-                    }
                     avio_read(pb, st->codec->extradata, st->codec->extradata_size);
                 }
 
diff --git a/libavformat/bink.c b/libavformat/bink.c
index 887f70a512..6db73cce3a 100644
--- a/libavformat/bink.c
+++ b/libavformat/bink.c
@@ -116,10 +116,8 @@ static int read_header(AVFormatContext *s)
 
     vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     vst->codec->codec_id   = AV_CODEC_ID_BINKVIDEO;
-    vst->codec->extradata  = av_mallocz(4 + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!vst->codec->extradata)
+    if (ff_alloc_extradata(vst->codec, 4))
         return AVERROR(ENOMEM);
-    vst->codec->extradata_size = 4;
     avio_read(pb, vst->codec->extradata, 4);
 
     bink->num_audio_tracks = avio_rl32(pb);
@@ -152,10 +150,8 @@ static int read_header(AVFormatContext *s)
                 ast->codec->channels       = 1;
                 ast->codec->channel_layout = AV_CH_LAYOUT_MONO;
             }
-            ast->codec->extradata = av_mallocz(4 + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (!ast->codec->extradata)
+            if (ff_alloc_extradata(ast->codec, 4))
                 return AVERROR(ENOMEM);
-            ast->codec->extradata_size = 4;
             AV_WL32(ast->codec->extradata, vst->codec->codec_tag);
         }
 
diff --git a/libavformat/bintext.c b/libavformat/bintext.c
index c1c6c0064a..d5046075a1 100644
--- a/libavformat/bintext.c
+++ b/libavformat/bintext.c
@@ -136,9 +136,7 @@ static int bintext_read_header(AVFormatContext *s)
         return AVERROR(ENOMEM);
     st->codec->codec_id    = AV_CODEC_ID_BINTEXT;
 
-    st->codec->extradata_size = 2;
-    st->codec->extradata = av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, 2))
         return AVERROR(ENOMEM);
     st->codec->extradata[0] = 16;
     st->codec->extradata[1] = 0;
@@ -194,8 +192,7 @@ static int xbin_read_header(AVFormatContext *s)
         st->codec->extradata_size += fontheight * (flags & 0x10 ? 512 : 256);
     st->codec->codec_id    = flags & 4 ? AV_CODEC_ID_XBIN : AV_CODEC_ID_BINTEXT;
 
-    st->codec->extradata = av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, st->codec->extradata_size))
         return AVERROR(ENOMEM);
     st->codec->extradata[0] = fontheight;
     st->codec->extradata[1] = flags;
@@ -227,9 +224,7 @@ static int adf_read_header(AVFormatContext *s)
         return AVERROR(ENOMEM);
     st->codec->codec_id    = AV_CODEC_ID_BINTEXT;
 
-    st->codec->extradata_size = 2 + 48 + 4096;
-    st->codec->extradata = av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, 2 + 48 + 4096))
         return AVERROR(ENOMEM);
     st->codec->extradata[0] = 16;
     st->codec->extradata[1] = BINTEXT_PALETTE|BINTEXT_FONT;
@@ -284,9 +279,7 @@ static int idf_read_header(AVFormatContext *s)
         return AVERROR(ENOMEM);
     st->codec->codec_id    = AV_CODEC_ID_IDF;
 
-    st->codec->extradata_size = 2 + 48 + 4096;
-    st->codec->extradata = av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, 2 + 48 + 4096))
         return AVERROR(ENOMEM);
     st->codec->extradata[0] = 16;
     st->codec->extradata[1] = BINTEXT_PALETTE|BINTEXT_FONT;
diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
index 337758ee12..e954c65683 100644
--- a/libavformat/cafdec.c
+++ b/libavformat/cafdec.c
@@ -130,8 +130,7 @@ static int read_kuki_chunk(AVFormatContext *s, int64_t size)
         }
         avio_read(pb, preamble, ALAC_PREAMBLE);
 
-        st->codec->extradata = av_mallocz(ALAC_HEADER + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, ALAC_HEADER))
             return AVERROR(ENOMEM);
 
         /* For the old style cookie, we skip 12 bytes, then read 36 bytes.
@@ -154,13 +153,10 @@ static int read_kuki_chunk(AVFormatContext *s, int64_t size)
             avio_read(pb, &st->codec->extradata[24], ALAC_NEW_KUKI - 12);
             avio_skip(pb, size - ALAC_NEW_KUKI);
         }
-        st->codec->extradata_size = ALAC_HEADER;
     } else {
-        st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, size))
             return AVERROR(ENOMEM);
         avio_read(pb, st->codec->extradata, size);
-        st->codec->extradata_size = size;
     }
 
     return 0;
diff --git a/libavformat/dfa.c b/libavformat/dfa.c
index 5799d983cf..12516afdc5 100644
--- a/libavformat/dfa.c
+++ b/libavformat/dfa.c
@@ -64,8 +64,8 @@ static int dfa_read_header(AVFormatContext *s)
     avio_skip(pb, 128 - 16); // padding
     st->duration = frames;
 
-    st->codec->extradata = av_malloc(2);
-    st->codec->extradata_size = 2;
+    if (ff_alloc_extradata(st->codec, 2))
+        return AVERROR(ENOMEM);
     AV_WL16(st->codec->extradata, version);
     if (version == 0x100)
         st->sample_aspect_ratio = (AVRational){2, 1};
diff --git a/libavformat/ffmdec.c b/libavformat/ffmdec.c
index 02cf790f87..b20ee131b6 100644
--- a/libavformat/ffmdec.c
+++ b/libavformat/ffmdec.c
@@ -278,9 +278,7 @@ static int ffm2_read_header(AVFormatContext *s)
             codec->flags2 = avio_rb32(pb);
             codec->debug = avio_rb32(pb);
             if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
-                codec->extradata_size = avio_rb32(pb);
-                codec->extradata = av_malloc(codec->extradata_size);
-                if (!codec->extradata)
+                if (ff_alloc_extradata(codec, avio_rb32(pb)))
                     return AVERROR(ENOMEM);
                 avio_read(pb, codec->extradata, codec->extradata_size);
             }
@@ -468,9 +466,7 @@ static int ffm_read_header(AVFormatContext *s)
             goto fail;
         }
         if (codec->flags & CODEC_FLAG_GLOBAL_HEADER) {
-            codec->extradata_size = avio_rb32(pb);
-            codec->extradata = av_malloc(codec->extradata_size);
-            if (!codec->extradata)
+            if (ff_alloc_extradata(codec, avio_rb32(pb)))
                 return AVERROR(ENOMEM);
             avio_read(pb, codec->extradata, codec->extradata_size);
         }
diff --git a/libavformat/flic.c b/libavformat/flic.c
index e04e2778c9..7235f2e188 100644
--- a/libavformat/flic.c
+++ b/libavformat/flic.c
@@ -125,10 +125,8 @@ static int flic_read_header(AVFormatContext *s)
     }
 
     /* send over the whole 128-byte FLIC header */
-    st->codec->extradata = av_malloc(FLIC_HEADER_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, FLIC_HEADER_SIZE))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = FLIC_HEADER_SIZE;
     memcpy(st->codec->extradata, header, FLIC_HEADER_SIZE);
 
     /* peek at the preamble to detect TFTD videos - they seem to always start with an audio chunk */
@@ -178,10 +176,8 @@ static int flic_read_header(AVFormatContext *s)
 
         /* send over abbreviated FLIC header chunk */
         av_free(st->codec->extradata);
-        st->codec->extradata = av_malloc(12);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, 12))
             return AVERROR(ENOMEM);
-        st->codec->extradata_size = 12;
         memcpy(st->codec->extradata, header, 12);
 
     } else if (magic_number == FLIC_FILE_MAGIC_1) {
diff --git a/libavformat/flvdec.c b/libavformat/flvdec.c
index d81a70b93b..d259927a84 100644
--- a/libavformat/flvdec.c
+++ b/libavformat/flvdec.c
@@ -246,9 +246,7 @@ static int flv_set_video_codec(AVFormatContext *s, AVStream *vstream,
             vcodec->codec_id = AV_CODEC_ID_VP6A;
         if (read) {
             if (vcodec->extradata_size != 1) {
-                vcodec->extradata = av_malloc(1 + FF_INPUT_BUFFER_PADDING_SIZE);
-                if (vcodec->extradata)
-                    vcodec->extradata_size = 1;
+                ff_alloc_extradata(vcodec, 1);
             }
             if (vcodec->extradata)
                 vcodec->extradata[0] = avio_r8(s->pb);
@@ -616,10 +614,8 @@ static int flv_read_close(AVFormatContext *s)
 static int flv_get_extradata(AVFormatContext *s, AVStream *st, int size)
 {
     av_free(st->codec->extradata);
-    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, size))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = size;
     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
     return 0;
 }
diff --git a/libavformat/idcin.c b/libavformat/idcin.c
index 85d538c4f3..9671fca6f8 100644
--- a/libavformat/idcin.c
+++ b/libavformat/idcin.c
@@ -196,10 +196,8 @@ static int idcin_read_header(AVFormatContext *s)
     st->codec->height = height;
 
     /* load up the Huffman tables into extradata */
-    st->codec->extradata = av_malloc(HUFFMAN_TABLE_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, HUFFMAN_TABLE_SIZE))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = HUFFMAN_TABLE_SIZE;
     ret = avio_read(pb, st->codec->extradata, HUFFMAN_TABLE_SIZE);
     if (ret < 0) {
         return ret;
diff --git a/libavformat/isom.c b/libavformat/isom.c
index ec372288ca..8cbf70b56e 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -452,11 +452,9 @@ int ff_mp4_read_dec_config_descr(AVFormatContext *fc, AVStream *st, AVIOContext
         if (!len || (uint64_t)len > (1<<30))
             return -1;
         av_free(st->codec->extradata);
-        st->codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, len))
             return AVERROR(ENOMEM);
         avio_read(pb, st->codec->extradata, len);
-        st->codec->extradata_size = len;
         if (st->codec->codec_id == AV_CODEC_ID_AAC) {
             MPEG4AudioConfig cfg;
             avpriv_mpeg4audio_get_config(&cfg, st->codec->extradata,
diff --git a/libavformat/libnut.c b/libavformat/libnut.c
index 71479982c3..be8f3cb283 100644
--- a/libavformat/libnut.c
+++ b/libavformat/libnut.c
@@ -232,8 +232,7 @@ static int nut_read_header(AVFormatContext * avf) {
 
         st->codec->extradata_size = s[i].codec_specific_len;
         if (st->codec->extradata_size) {
-            st->codec->extradata = av_mallocz(st->codec->extradata_size);
-            if(!st->codec->extradata){
+            if(ff_alloc_extradata(st->codec, st->codec->extradata_size)){
                 nut_demuxer_uninit(nut);
                 priv->nut = NULL;
                 return AVERROR(ENOMEM);
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 1879328ece..de798e5b79 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1819,11 +1819,8 @@ static int matroska_read_header(AVFormatContext *s)
                 st->codec->extradata = extradata;
                 st->codec->extradata_size = extradata_size;
             } else if(track->codec_priv.data && track->codec_priv.size > 0){
-                st->codec->extradata = av_mallocz(track->codec_priv.size +
-                                                  FF_INPUT_BUFFER_PADDING_SIZE);
-                if(st->codec->extradata == NULL)
+                if (ff_alloc_extradata(st->codec, track->codec_priv.size))
                     return AVERROR(ENOMEM);
-                st->codec->extradata_size = track->codec_priv.size;
                 memcpy(st->codec->extradata,
                        track->codec_priv.data + extradata_offset,
                        track->codec_priv.size);
@@ -1916,10 +1913,8 @@ static int matroska_read_header(AVFormatContext *s)
             av_dict_set(&st->metadata, "mimetype", attachements[j].mime, 0);
             st->codec->codec_id = AV_CODEC_ID_NONE;
             st->codec->codec_type = AVMEDIA_TYPE_ATTACHMENT;
-            st->codec->extradata  = av_malloc(attachements[j].bin.size + FF_INPUT_BUFFER_PADDING_SIZE);
-            if(st->codec->extradata == NULL)
+            if (ff_alloc_extradata(st->codec, attachements[j].bin.size))
                 break;
-            st->codec->extradata_size = attachements[j].bin.size;
             memcpy(st->codec->extradata, attachements[j].bin.data, attachements[j].bin.size);
 
             for (i=0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++) {
diff --git a/libavformat/mov.c b/libavformat/mov.c
index f222cf8452..f8535f0413 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -1077,11 +1077,8 @@ static int mov_read_wave(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         st->codec->codec_id == AV_CODEC_ID_SPEEX) {
         // pass all frma atom to codec, needed at least for QDMC and QDM2
         av_free(st->codec->extradata);
-        st->codec->extradata_size = 0;
-        st->codec->extradata = av_mallocz(atom.size + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, atom.size))
             return AVERROR(ENOMEM);
-        st->codec->extradata_size = atom.size;
         avio_read(pb, st->codec->extradata, atom.size);
     } else if (atom.size > 8) { /* to read frma, esds atoms */
         int ret;
@@ -1117,11 +1114,8 @@ static int mov_read_glbl(MOVContext *c, AVIOContext *pb, MOVAtom atom)
             return mov_read_default(c, pb, atom);
     }
     av_free(st->codec->extradata);
-    st->codec->extradata_size = 0;
-    st->codec->extradata = av_mallocz(atom.size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, atom.size))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = atom.size;
     avio_read(pb, st->codec->extradata, atom.size);
     return 0;
 }
@@ -1143,11 +1137,8 @@ static int mov_read_dvc1(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         return 0;
 
     av_free(st->codec->extradata);
-    st->codec->extradata_size = 0;
-    st->codec->extradata = av_mallocz(atom.size - 7 + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, atom.size - 7))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = atom.size - 7;
     avio_seek(pb, 6, SEEK_CUR);
     avio_read(pb, st->codec->extradata, st->codec->extradata_size);
     return 0;
@@ -1172,11 +1163,8 @@ static int mov_read_strf(MOVContext *c, AVIOContext *pb, MOVAtom atom)
         return AVERROR_INVALIDDATA;
 
     av_free(st->codec->extradata);
-    st->codec->extradata_size = 0;
-    st->codec->extradata = av_mallocz(atom.size - 40 + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, atom.size - 40))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = atom.size - 40;
     avio_skip(pb, 40);
     avio_read(pb, st->codec->extradata, atom.size - 40);
     return 0;
@@ -1491,9 +1479,7 @@ static int mov_parse_stsd_data(MOVContext *c, AVIOContext *pb,
                                 int size)
 {
     if (st->codec->codec_tag == MKTAG('t','m','c','d')) {
-        st->codec->extradata_size = size;
-        st->codec->extradata = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, size))
             return AVERROR(ENOMEM);
         avio_read(pb, st->codec->extradata, size);
         if (size > 16) {
diff --git a/libavformat/mpc.c b/libavformat/mpc.c
index b0f6f533e1..8abc488553 100644
--- a/libavformat/mpc.c
+++ b/libavformat/mpc.c
@@ -95,8 +95,8 @@ static int mpc_read_header(AVFormatContext *s)
     st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
     st->codec->bits_per_coded_sample = 16;
 
-    st->codec->extradata_size = 16;
-    st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);
+    if (ff_alloc_extradata(st->codec, 16))
+        return AVERROR(ENOMEM);
     avio_read(s->pb, st->codec->extradata, 16);
     st->codec->sample_rate = mpc_rate[st->codec->extradata[2] & 3];
     avpriv_set_pts_info(st, 32, MPC_FRAMESIZE, st->codec->sample_rate);
diff --git a/libavformat/mpc8.c b/libavformat/mpc8.c
index 5ee4e00a5d..7017c187f7 100644
--- a/libavformat/mpc8.c
+++ b/libavformat/mpc8.c
@@ -241,8 +241,8 @@ static int mpc8_read_header(AVFormatContext *s)
     st->codec->codec_id = AV_CODEC_ID_MUSEPACK8;
     st->codec->bits_per_coded_sample = 16;
 
-    st->codec->extradata_size = 2;
-    st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    if (ff_alloc_extradata(st->codec, 2))
+        return AVERROR(ENOMEM);
     avio_read(pb, st->codec->extradata, st->codec->extradata_size);
 
     st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
diff --git a/libavformat/mpegts.c b/libavformat/mpegts.c
index 67e94fb39e..cd881d8130 100644
--- a/libavformat/mpegts.c
+++ b/libavformat/mpegts.c
@@ -1454,9 +1454,7 @@ int ff_parse_mpeg2_descriptor(AVFormatContext *fc, AVStream *st, int stream_type
             if (st->codec->extradata_size == 4 && memcmp(st->codec->extradata, *pp, 4))
                 avpriv_request_sample(fc, "DVB sub with multiple IDs");
         } else {
-            st->codec->extradata = av_malloc(4 + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (st->codec->extradata) {
-                st->codec->extradata_size = 4;
+            if (!ff_alloc_extradata(st->codec, 4)) {
                 memcpy(st->codec->extradata, *pp, 4);
             }
         }
diff --git a/libavformat/mvi.c b/libavformat/mvi.c
index bd1f3c66f9..5efc443152 100644
--- a/libavformat/mvi.c
+++ b/libavformat/mvi.c
@@ -52,9 +52,7 @@ static int read_header(AVFormatContext *s)
     if (!vst)
         return AVERROR(ENOMEM);
 
-    vst->codec->extradata_size = 2;
-    vst->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!vst->codec->extradata)
+    if (ff_alloc_extradata(vst->codec, 2))
         return AVERROR(ENOMEM);
 
     version                  = avio_r8(pb);
diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index dac98acaf3..72faf4cce2 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -1599,10 +1599,8 @@ static int mxf_parse_structural_metadata(MXFContext *mxf)
             }
         }
         if (descriptor->extradata) {
-            st->codec->extradata = av_mallocz(descriptor->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-            if (st->codec->extradata) {
+            if (!ff_alloc_extradata(st->codec, descriptor->extradata_size)) {
                 memcpy(st->codec->extradata, descriptor->extradata, descriptor->extradata_size);
-                st->codec->extradata_size = descriptor->extradata_size;
             }
         } else if(st->codec->codec_id == AV_CODEC_ID_H264) {
             ff_generate_avci_extradata(st);
diff --git a/libavformat/nutdec.c b/libavformat/nutdec.c
index e6b10c7e1f..f380279343 100644
--- a/libavformat/nutdec.c
+++ b/libavformat/nutdec.c
@@ -415,9 +415,7 @@ static int decode_stream_header(NUTContext *nut)
 
     GET_V(st->codec->extradata_size, tmp < (1 << 30));
     if (st->codec->extradata_size) {
-        st->codec->extradata = av_mallocz(st->codec->extradata_size +
-                                          FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!st->codec->extradata)
+        if (ff_alloc_extradata(st->codec, st->codec->extradata_size))
             return AVERROR(ENOMEM);
         avio_read(bc, st->codec->extradata, st->codec->extradata_size);
     }
diff --git a/libavformat/nuv.c b/libavformat/nuv.c
index fc9e916013..32d0e02f68 100644
--- a/libavformat/nuv.c
+++ b/libavformat/nuv.c
@@ -86,10 +86,8 @@ static int get_codec_data(AVIOContext *pb, AVStream *vst,
                     av_freep(&vst->codec->extradata);
                     vst->codec->extradata_size = 0;
                 }
-                vst->codec->extradata = av_malloc(size);
-                if (!vst->codec->extradata)
+                if (ff_alloc_extradata(vst->codec, size))
                     return AVERROR(ENOMEM);
-                vst->codec->extradata_size = size;
                 avio_read(pb, vst->codec->extradata, size);
                 size = 0;
                 if (!myth)
diff --git a/libavformat/oggparseflac.c b/libavformat/oggparseflac.c
index 08fd77e9ed..894b43850c 100644
--- a/libavformat/oggparseflac.c
+++ b/libavformat/oggparseflac.c
@@ -62,10 +62,8 @@ flac_header (AVFormatContext * s, int idx)
         st->codec->codec_id = AV_CODEC_ID_FLAC;
         st->need_parsing = AVSTREAM_PARSE_HEADERS;
 
-        st->codec->extradata =
-            av_malloc(FLAC_STREAMINFO_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
-        memcpy(st->codec->extradata, streaminfo_start, FLAC_STREAMINFO_SIZE);
-        st->codec->extradata_size = FLAC_STREAMINFO_SIZE;
+        ff_alloc_extradata(st->codec, FLAC_STREAMINFO_SIZE);
+        memcpy(st->codec->extradata, streaminfo_start, st->codec->extradata_size);
 
         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
     } else if (mdt == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
diff --git a/libavformat/oggparseogm.c b/libavformat/oggparseogm.c
index a9091e43a1..b8c502a5ff 100644
--- a/libavformat/oggparseogm.c
+++ b/libavformat/oggparseogm.c
@@ -99,9 +99,8 @@ ogm_header(AVFormatContext *s, int idx)
             if (size > 52) {
                 av_assert0(FF_INPUT_BUFFER_PADDING_SIZE <= 52);
                 size -= 52;
-                st->codec->extradata_size = size;
-                st->codec->extradata = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
-                bytestream2_get_buffer(&p, st->codec->extradata, size);
+                ff_alloc_extradata(st->codec, size);
+                bytestream2_get_buffer(&p, st->codec->extradata, st->codec->extradata_size);
             }
         }
     } else if (bytestream2_peek_byte(&p) == 3) {
diff --git a/libavformat/oggparsespeex.c b/libavformat/oggparsespeex.c
index 63e6370482..7cbc7e0673 100644
--- a/libavformat/oggparsespeex.c
+++ b/libavformat/oggparsespeex.c
@@ -77,9 +77,7 @@ static int speex_header(AVFormatContext *s, int idx) {
         if (frames_per_packet)
             spxp->packet_size *= frames_per_packet;
 
-        st->codec->extradata_size = os->psize;
-        st->codec->extradata = av_malloc(st->codec->extradata_size
-                                         + FF_INPUT_BUFFER_PADDING_SIZE);
+        ff_alloc_extradata(st->codec, os->psize);
         memcpy(st->codec->extradata, p, st->codec->extradata_size);
 
         avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
diff --git a/libavformat/omadec.c b/libavformat/omadec.c
index e4291d9b55..4017db3f2b 100644
--- a/libavformat/omadec.c
+++ b/libavformat/omadec.c
@@ -349,12 +349,10 @@ static int oma_read_header(AVFormatContext *s)
 
         /* fake the ATRAC3 extradata
          * (wav format, makes stream copy to wav work) */
-        st->codec->extradata_size = 14;
-        edata = av_mallocz(14 + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!edata)
+        if (ff_alloc_extradata(st->codec, 14))
             return AVERROR(ENOMEM);
 
-        st->codec->extradata = edata;
+        edata = st->codec->extradata;
         AV_WL16(&edata[0],  1);             // always 1
         AV_WL32(&edata[2],  samplerate);    // samples rate
         AV_WL16(&edata[6],  jsflag);        // coding mode
diff --git a/libavformat/redspark.c b/libavformat/redspark.c
index 3963261b9a..6d4c8c5c1a 100644
--- a/libavformat/redspark.c
+++ b/libavformat/redspark.c
@@ -113,9 +113,7 @@ static int redspark_read_header(AVFormatContext *s)
         goto fail;
     }
 
-    codec->extradata_size = 32 * codec->channels;
-    codec->extradata = av_malloc(codec->extradata_size);
-    if (!codec->extradata) {
+    if (ff_alloc_extradata(codec, 32 * codec->channels)) {
         ret = AVERROR(ENOMEM);
         goto fail;
     }
diff --git a/libavformat/riffdec.c b/libavformat/riffdec.c
index e7c52e09c3..de8eb5f588 100644
--- a/libavformat/riffdec.c
+++ b/libavformat/riffdec.c
@@ -115,12 +115,9 @@ int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size)
             cbSize -= 22;
             size   -= 22;
         }
-        codec->extradata_size = cbSize;
         if (cbSize > 0) {
             av_free(codec->extradata);
-            codec->extradata = av_mallocz(codec->extradata_size +
-                                          FF_INPUT_BUFFER_PADDING_SIZE);
-            if (!codec->extradata)
+            if (ff_alloc_extradata(codec, cbSize))
                 return AVERROR(ENOMEM);
             avio_read(pb, codec->extradata, codec->extradata_size);
             size -= cbSize;
diff --git a/libavformat/rl2.c b/libavformat/rl2.c
index fb7409eaa6..ff4006497f 100644
--- a/libavformat/rl2.c
+++ b/libavformat/rl2.c
@@ -125,9 +125,7 @@ static av_cold int rl2_read_header(AVFormatContext *s)
     if(signature == RLV3_TAG && back_size > 0)
         st->codec->extradata_size += back_size;
 
-    st->codec->extradata = av_mallocz(st->codec->extradata_size +
-                                          FF_INPUT_BUFFER_PADDING_SIZE);
-    if(!st->codec->extradata)
+    if(ff_alloc_extradata(st->codec, st->codec->extradata_size))
         return AVERROR(ENOMEM);
 
     if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
diff --git a/libavformat/rmdec.c b/libavformat/rmdec.c
index 278fc37b45..a79fbaf4db 100644
--- a/libavformat/rmdec.c
+++ b/libavformat/rmdec.c
@@ -86,11 +86,9 @@ static int rm_read_extradata(AVIOContext *pb, AVCodecContext *avctx, unsigned si
 {
     if (size >= 1<<24)
         return -1;
-    avctx->extradata = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!avctx->extradata)
+    if (ff_alloc_extradata(avctx, size))
         return AVERROR(ENOMEM);
     avctx->extradata_size = avio_read(pb, avctx->extradata, size);
-    memset(avctx->extradata + avctx->extradata_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
     if (avctx->extradata_size != size)
         return AVERROR(EIO);
     return 0;
diff --git a/libavformat/rsd.c b/libavformat/rsd.c
index 5b53cef9c0..37e544acb1 100644
--- a/libavformat/rsd.c
+++ b/libavformat/rsd.c
@@ -101,9 +101,7 @@ static int rsd_read_header(AVFormatContext *s)
         /* RSD3GADP is mono, so only alloc enough memory
            to store the coeff table for a single channel. */
 
-        codec->extradata_size = 32;
-        codec->extradata = av_malloc(codec->extradata_size);
-        if (!codec->extradata)
+        if (ff_alloc_extradata(codec, 32))
             return AVERROR(ENOMEM);
 
         start = avio_rl32(pb);
diff --git a/libavformat/rtpdec_latm.c b/libavformat/rtpdec_latm.c
index a2ad07104a..fdeff3a151 100644
--- a/libavformat/rtpdec_latm.c
+++ b/libavformat/rtpdec_latm.c
@@ -130,10 +130,7 @@ static int parse_fmtp_config(AVStream *st, char *value)
         goto end;
     }
     av_freep(&st->codec->extradata);
-    st->codec->extradata_size = (get_bits_left(&gb) + 7)/8;
-    st->codec->extradata = av_mallocz(st->codec->extradata_size +
-                                      FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata) {
+    if (ff_alloc_extradata(st->codec, (get_bits_left(&gb) + 7)/8)) {
         ret = AVERROR(ENOMEM);
         goto end;
     }
diff --git a/libavformat/rtpdec_mpeg4.c b/libavformat/rtpdec_mpeg4.c
index 571b7392e0..0ea5594c06 100644
--- a/libavformat/rtpdec_mpeg4.c
+++ b/libavformat/rtpdec_mpeg4.c
@@ -105,10 +105,8 @@ static int parse_fmtp_config(AVCodecContext *codec, char *value)
     /* decode the hexa encoded parameter */
     int len = ff_hex_to_data(NULL, value);
     av_free(codec->extradata);
-    codec->extradata = av_mallocz(len + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!codec->extradata)
+    if (ff_alloc_extradata(codec, len))
         return AVERROR(ENOMEM);
-    codec->extradata_size = len;
     ff_hex_to_data(codec->extradata, value);
     return 0;
 }
diff --git a/libavformat/rtpdec_qdm2.c b/libavformat/rtpdec_qdm2.c
index 6ce776db44..e1dd62fb8e 100644
--- a/libavformat/rtpdec_qdm2.c
+++ b/libavformat/rtpdec_qdm2.c
@@ -29,6 +29,7 @@
 #include "libavutil/avassert.h"
 #include "libavutil/intreadwrite.h"
 #include "libavcodec/avcodec.h"
+#include "internal.h"
 #include "rtp.h"
 #include "rtpdec.h"
 #include "rtpdec_formats.h"
@@ -104,9 +105,7 @@ static int qdm2_parse_config(PayloadContext *qdm, AVStream *st,
                 if (item_len < 30)
                     return AVERROR_INVALIDDATA;
                 av_freep(&st->codec->extradata);
-                st->codec->extradata_size = 26 + item_len;
-                if (!(st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE))) {
-                    st->codec->extradata_size = 0;
+                if (ff_alloc_extradata(st->codec, 26 + item_len)) {
                     return AVERROR(ENOMEM);
                 }
                 AV_WB32(st->codec->extradata, 12);
diff --git a/libavformat/rtpdec_svq3.c b/libavformat/rtpdec_svq3.c
index 106b7857cb..98e8b58673 100644
--- a/libavformat/rtpdec_svq3.c
+++ b/libavformat/rtpdec_svq3.c
@@ -28,6 +28,7 @@
 
 #include <string.h>
 #include "libavutil/intreadwrite.h"
+#include "internal.h"
 #include "rtp.h"
 #include "rtpdec.h"
 #include "rtpdec_formats.h"
@@ -60,11 +61,9 @@ static int svq3_parse_packet (AVFormatContext *s, PayloadContext *sv,
         av_freep(&st->codec->extradata);
         st->codec->extradata_size = 0;
 
-        if (len < 2 || !(st->codec->extradata =
-                         av_malloc(len + 8 + FF_INPUT_BUFFER_PADDING_SIZE)))
+        if (len < 2 || ff_alloc_extradata(st->codec, len + 8))
             return AVERROR_INVALIDDATA;
 
-        st->codec->extradata_size = len + 8;
         memcpy(st->codec->extradata, "SEQH", 4);
         AV_WB32(st->codec->extradata + 4, len);
         memcpy(st->codec->extradata + 8, buf, len);
diff --git a/libavformat/rtpdec_xiph.c b/libavformat/rtpdec_xiph.c
index 52a94b3159..887a65ed65 100644
--- a/libavformat/rtpdec_xiph.c
+++ b/libavformat/rtpdec_xiph.c
@@ -33,6 +33,7 @@
 #include "libavutil/base64.h"
 #include "libavcodec/bytestream.h"
 
+#include "internal.h"
 #include "rtpdec.h"
 #include "rtpdec_formats.h"
 
@@ -288,11 +289,11 @@ parse_packed_headers(const uint8_t * packed_headers,
      * -- FF_INPUT_BUFFER_PADDING_SIZE required */
     extradata_alloc = length + length/255 + 3 + FF_INPUT_BUFFER_PADDING_SIZE;
 
-    ptr = codec->extradata = av_malloc(extradata_alloc);
-    if (!ptr) {
+    if (ff_alloc_extradata(codec, extradata_alloc)) {
         av_log(codec, AV_LOG_ERROR, "Out of memory\n");
         return AVERROR(ENOMEM);
     }
+    ptr = codec->extradata;
     *ptr++ = 2;
     ptr += av_xiphlacing(ptr, length1);
     ptr += av_xiphlacing(ptr, length2);
diff --git a/libavformat/sbgdec.c b/libavformat/sbgdec.c
index 30c3b49cd7..36cd8a3ce2 100644
--- a/libavformat/sbgdec.c
+++ b/libavformat/sbgdec.c
@@ -1333,11 +1333,9 @@ static int encode_intervals(struct sbg_script *s, AVCodecContext *avc,
         if (edata_size < 0)
             return AVERROR(ENOMEM);
     }
-    edata = av_malloc(edata_size);
-    if (!edata)
+    if (ff_alloc_extradata(avc, edata_size))
         return AVERROR(ENOMEM);
-    avc->extradata = edata;
-    avc->extradata_size = edata_size;
+    edata = avc->extradata;
 
 #define ADD_EDATA32(v) do { AV_WL32(edata, (v)); edata += 4; } while(0)
 #define ADD_EDATA64(v) do { AV_WL64(edata, (v)); edata += 8; } while(0)
diff --git a/libavformat/sierravmd.c b/libavformat/sierravmd.c
index fad3dd3d8a..8749ec1640 100644
--- a/libavformat/sierravmd.c
+++ b/libavformat/sierravmd.c
@@ -127,10 +127,8 @@ static int vmd_read_header(AVFormatContext *s)
             vst->codec->width >>= 1;
             vst->codec->height >>= 1;
         }
-        vst->codec->extradata = av_mallocz(VMD_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!vst->codec->extradata)
+        if (ff_alloc_extradata(vst->codec, VMD_HEADER_SIZE))
             return AVERROR(ENOMEM);
-        vst->codec->extradata_size = VMD_HEADER_SIZE;
         memcpy(vst->codec->extradata, vmd->vmd_header, VMD_HEADER_SIZE);
     }
 
diff --git a/libavformat/smacker.c b/libavformat/smacker.c
index c5bc5e0e29..527faf7dd8 100644
--- a/libavformat/smacker.c
+++ b/libavformat/smacker.c
@@ -217,10 +217,7 @@ static int smacker_read_header(AVFormatContext *s)
 
 
     /* load trees to extradata, they will be unpacked by decoder */
-    st->codec->extradata = av_mallocz(smk->treesize + 16 +
-                                      FF_INPUT_BUFFER_PADDING_SIZE);
-    st->codec->extradata_size = smk->treesize + 16;
-    if(!st->codec->extradata){
+    if(ff_alloc_extradata(st->codec, smk->treesize + 16)){
         av_log(s, AV_LOG_ERROR, "Cannot allocate %i bytes of extradata\n", smk->treesize + 16);
         av_freep(&smk->frm_size);
         av_freep(&smk->frm_flags);
diff --git a/libavformat/smush.c b/libavformat/smush.c
index 9c8997cc00..e9c1937398 100644
--- a/libavformat/smush.c
+++ b/libavformat/smush.c
@@ -145,11 +145,9 @@ static int smush_read_header(AVFormatContext *ctx)
     avpriv_set_pts_info(vst, 64, 66667, 1000000);
 
     if (!smush->version) {
-        vst->codec->extradata = av_malloc(1024 + 2 + FF_INPUT_BUFFER_PADDING_SIZE);
-        if (!vst->codec->extradata)
+        if (ff_alloc_extradata(vst->codec, 1024 + 2))
             return AVERROR(ENOMEM);
 
-        vst->codec->extradata_size = 1024 + 2;
         AV_WL16(vst->codec->extradata, subversion);
         for (i = 0; i < 256; i++)
             AV_WL32(vst->codec->extradata + 2 + i * 4, palette[i]);
diff --git a/libavformat/tta.c b/libavformat/tta.c
index bbb6a2292c..7174fd5438 100644
--- a/libavformat/tta.c
+++ b/libavformat/tta.c
@@ -109,12 +109,8 @@ static int tta_read_header(AVFormatContext *s)
 
     framepos = avio_tell(s->pb) + 4*c->totalframes + 4;
 
-    st->codec->extradata_size = avio_tell(s->pb) - start_offset;
-    st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata) {
-        st->codec->extradata_size = 0;
+    if (ff_alloc_extradata(st->codec, avio_tell(s->pb) - start_offset))
         return AVERROR(ENOMEM);
-    }
 
     avio_seek(s->pb, start_offset, SEEK_SET);
     avio_read(s->pb, st->codec->extradata, st->codec->extradata_size);
diff --git a/libavformat/utils.c b/libavformat/utils.c
index 6a7f58027c..50f7d8732e 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -2950,12 +2950,9 @@ int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
         if(st->parser && st->parser->parser->split && !st->codec->extradata){
             int i= st->parser->parser->split(st->codec, pkt->data, pkt->size);
             if (i > 0 && i < FF_MAX_EXTRADATA_SIZE) {
-                st->codec->extradata_size= i;
-                st->codec->extradata= av_malloc(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
-                if (!st->codec->extradata)
+                if (ff_alloc_extradata(st->codec, i))
                     return AVERROR(ENOMEM);
                 memcpy(st->codec->extradata, pkt->data, st->codec->extradata_size);
-                memset(st->codec->extradata + i, 0, FF_INPUT_BUFFER_PADDING_SIZE);
             }
         }
 
@@ -4271,10 +4268,7 @@ void ff_generate_avci_extradata(AVStream *st)
     if (!size)
         return;
     av_freep(&st->codec->extradata);
-    st->codec->extradata_size = 0;
-    st->codec->extradata = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, size))
         return;
     memcpy(st->codec->extradata, data, size);
-    st->codec->extradata_size = size;
 }
diff --git a/libavformat/vc1test.c b/libavformat/vc1test.c
index 7c6bcde089..bf1bfe0318 100644
--- a/libavformat/vc1test.c
+++ b/libavformat/vc1test.c
@@ -61,8 +61,8 @@ static int vc1t_read_header(AVFormatContext *s)
     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
     st->codec->codec_id = AV_CODEC_ID_WMV3;
 
-    st->codec->extradata = av_malloc(VC1_EXTRADATA_SIZE);
-    st->codec->extradata_size = VC1_EXTRADATA_SIZE;
+    if (ff_alloc_extradata(st->codec, VC1_EXTRADATA_SIZE))
+        return AVERROR(ENOMEM);
     avio_read(pb, st->codec->extradata, VC1_EXTRADATA_SIZE);
     st->codec->height = avio_rl32(pb);
     st->codec->width = avio_rl32(pb);
diff --git a/libavformat/vqf.c b/libavformat/vqf.c
index be7d8a0a80..4cd0a6deec 100644
--- a/libavformat/vqf.c
+++ b/libavformat/vqf.c
@@ -220,9 +220,8 @@ static int vqf_read_header(AVFormatContext *s)
     avpriv_set_pts_info(st, 64, size, st->codec->sample_rate);
 
     /* put first 12 bytes of COMM chunk in extradata */
-    if (!(st->codec->extradata = av_malloc(12 + FF_INPUT_BUFFER_PADDING_SIZE)))
+    if (ff_alloc_extradata(st->codec, 12))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = 12;
     memcpy(st->codec->extradata, comm_chunk, 12);
 
     ff_metadata_conv_ctx(s, NULL, vqf_metadata_conv);
diff --git a/libavformat/wavdec.c b/libavformat/wavdec.c
index ef28349fec..8ae7b4557b 100644
--- a/libavformat/wavdec.c
+++ b/libavformat/wavdec.c
@@ -353,10 +353,7 @@ static int wav_read_header(AVFormatContext *s)
             vst->codec->codec_id = AV_CODEC_ID_SMVJPEG;
             vst->codec->width  = avio_rl24(pb);
             vst->codec->height = avio_rl24(pb);
-            vst->codec->extradata_size = 4;
-            vst->codec->extradata = av_malloc(vst->codec->extradata_size +
-                                              FF_INPUT_BUFFER_PADDING_SIZE);
-            if (!vst->codec->extradata) {
+            if (ff_alloc_extradata(vst->codec, 4)) {
                 av_log(s, AV_LOG_ERROR, "Could not allocate extradata.\n");
                 return AVERROR(ENOMEM);
             }
diff --git a/libavformat/westwood_vqa.c b/libavformat/westwood_vqa.c
index d8791da131..2e72928a4c 100644
--- a/libavformat/westwood_vqa.c
+++ b/libavformat/westwood_vqa.c
@@ -101,10 +101,8 @@ static int wsvqa_read_header(AVFormatContext *s)
     avio_seek(pb, 20, SEEK_SET);
 
     /* the VQA header needs to go to the decoder */
-    st->codec->extradata = av_mallocz(VQA_HEADER_SIZE + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codec->extradata)
+    if (ff_alloc_extradata(st->codec, VQA_HEADER_SIZE))
         return AVERROR(ENOMEM);
-    st->codec->extradata_size = VQA_HEADER_SIZE;
     header = (unsigned char *)st->codec->extradata;
     if (avio_read(pb, st->codec->extradata, VQA_HEADER_SIZE) !=
         VQA_HEADER_SIZE) {
@@ -221,9 +219,7 @@ static int wsvqa_read_packet(AVFormatContext *s,
                         break;
                     case SND2_TAG:
                         st->codec->codec_id = AV_CODEC_ID_ADPCM_IMA_WS;
-                        st->codec->extradata_size = 2;
-                        st->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
-                        if (!st->codec->extradata)
+                        if (ff_alloc_extradata(st->codec, 2))
                             return AVERROR(ENOMEM);
                         AV_WL16(st->codec->extradata, wsvqa->version);
                         break;
diff --git a/libavformat/xmv.c b/libavformat/xmv.c
index b42b0b1968..20f9bea55b 100644
--- a/libavformat/xmv.c
+++ b/libavformat/xmv.c
@@ -383,9 +383,7 @@ static int xmv_process_packet_header(AVFormatContext *s)
                 if (vst->codec->extradata_size < 4) {
                     av_free(vst->codec->extradata);
 
-                    vst->codec->extradata =
-                        av_malloc(4 + FF_INPUT_BUFFER_PADDING_SIZE);
-                    vst->codec->extradata_size = 4;
+                    ff_alloc_extradata(vst->codec, 4);
                 }
 
                 memcpy(vst->codec->extradata, xmv->video.extradata, 4);
diff --git a/libavformat/yop.c b/libavformat/yop.c
index e962b093e8..07086d53b8 100644
--- a/libavformat/yop.c
+++ b/libavformat/yop.c
@@ -69,12 +69,7 @@ static int yop_read_header(AVFormatContext *s)
         return AVERROR(ENOMEM);
 
     // Extra data that will be passed to the decoder
-    video_stream->codec->extradata_size = 8;
-
-    video_stream->codec->extradata = av_mallocz(video_stream->codec->extradata_size +
-                                                FF_INPUT_BUFFER_PADDING_SIZE);
-
-    if (!video_stream->codec->extradata)
+    if (ff_alloc_extradata(video_stream->codec, 8))
         return AVERROR(ENOMEM);
 
     // Audio