diff options
Diffstat (limited to 'libavformat/mtv.c')
| -rw-r--r-- | libavformat/mtv.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/libavformat/mtv.c b/libavformat/mtv.c new file mode 100644 index 0000000000..fff72b4739 --- /dev/null +++ b/libavformat/mtv.c @@ -0,0 +1,186 @@ +/* + * mtv demuxer + * Copyright (c) 2006 Reynaldo H. Verdejo Pinochet + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file mtv.c + * MTV demuxer. + */ + +#include "avformat.h" +#include "bswap.h" + +#define MTV_ASUBCHUNK_DATA_SIZE 500 +#define MTV_HEADER_SIZE 512 +#define MTV_AUDIO_PADDING_SIZE 12 +#define AUDIO_SAMPLING_RATE 44100 +#define VIDEO_SID 0 +#define AUDIO_SID 1 + +typedef struct MTVDemuxContext { + + unsigned int file_size; ///< filesize, not always right + unsigned int segments; ///< number of 512 byte segments + unsigned int audio_identifier; ///< 'MP3' on all files I have seen + unsigned int audio_br; ///< bitrate of audio chanel (mp3) + unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555 + unsigned int img_bpp; ///< frame bits per pixel + unsigned int img_width; // + unsigned int img_height; // + unsigned int img_segment_size; ///< size of image segment + unsigned int video_fps; // + unsigned int audio_subsegments; ///< audio subsegments on one segment + + uint8_t audio_packet_count; + +} MTVDemuxContext; + +static int mtv_probe(AVProbeData *p) +{ + if(p->buf_size < 3) + return 0; + + /* Magic is 'AMV' */ + + if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V') + return 0; + + return AVPROBE_SCORE_MAX; +} + +static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap) +{ + MTVDemuxContext *mtv = s->priv_data; + ByteIOContext *pb = &s->pb; + AVStream *st; + + + url_fskip(pb, 3); + mtv->file_size = get_le32(pb); + mtv->segments = get_le32(pb); + url_fskip(pb, 32); + mtv->audio_identifier = get_le24(pb); + mtv->audio_br = get_le16(pb); + mtv->img_colorfmt = get_le24(pb); + mtv->img_bpp = get_byte(pb); + mtv->img_width = get_le16(pb); + mtv->img_height = get_le16(pb); + mtv->img_segment_size = get_le16(pb); + url_fskip(pb, 4); + mtv->audio_subsegments = get_le16(pb); + mtv->video_fps = (mtv->audio_br / 4) / mtv->audio_subsegments; + + /* FIXME Add sanity check here */ + + /* first packet is allways audio*/ + + mtv->audio_packet_count = 1; + + /* all systems go! init decoders */ + + /* video - raw rgb565 */ + + st = av_new_stream(s, VIDEO_SID); + if(!st) + return AVERROR_NOMEM; + + av_set_pts_info(st, 64, 1, mtv->video_fps); + st->codec->codec_type = CODEC_TYPE_VIDEO; + st->codec->codec_id = CODEC_ID_RAWVIDEO; + st->codec->width = mtv->img_width; + st->codec->height = mtv->img_height; + st->codec->bits_per_sample = mtv->img_bpp; + st->codec->sample_rate = mtv->video_fps; + + /* audio - mp3 */ + + st = av_new_stream(s, AUDIO_SID); + if(!st) + return AVERROR_NOMEM; + + av_set_pts_info(st, 64, 1, AUDIO_SAMPLING_RATE); + st->codec->codec_type = CODEC_TYPE_AUDIO; + st->codec->codec_id = CODEC_ID_MP3; + st->codec->bit_rate = mtv->audio_br; + st->need_parsing=1; + + /* Jump over header */ + + if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE) + return AVERROR_IO; + + return(0); + +} + +static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt) +{ + MTVDemuxContext *mtv = s->priv_data; + ByteIOContext *pb = &s->pb; + int ret; +#ifndef WORDS_BIGENDIAN + int i; +#endif + + ret = 0; + + if(mtv->audio_subsegments >= mtv->audio_packet_count) + { + url_fskip(pb, MTV_AUDIO_PADDING_SIZE); + + ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE); + if(ret != MTV_ASUBCHUNK_DATA_SIZE) + return AVERROR_IO; + + mtv->audio_packet_count++; + pkt->stream_index = AUDIO_SID; + + }else + { + ret = av_get_packet(pb, pkt, mtv->img_segment_size); + if(ret != mtv->img_segment_size) + return AVERROR_IO; + +#ifndef WORDS_BIGENDIAN + + /* pkt->data is GGGRRRR BBBBBGGG + * and we need RRRRRGGG GGGBBBBB + * for PIX_FMT_RGB565 so here we + * just swap bytes as they come + */ + + for(i=0;i<mtv->img_segment_size/2;i++) + *((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i)); +#endif + mtv->audio_packet_count = 1; + pkt->stream_index = VIDEO_SID; + } + + return(ret); +} + +AVInputFormat mtv_demuxer = { + "MTV", + "MTV format", + sizeof(MTVDemuxContext), + mtv_probe, + mtv_read_header, + mtv_read_packet, +}; |