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-rw-r--r--libavcodec/api-example.c579
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diff --git a/libavcodec/api-example.c b/libavcodec/api-example.c
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-/*
- * copyright (c) 2001 Fabrice Bellard
- *
- * This file is part of Libav.
- *
- * Libav 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.
- *
- * Libav 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 Libav; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * libavcodec API use example.
- *
- * @example libavcodec/api-example.c
- * Note that this library only handles codecs (mpeg, mpeg4, etc...),
- * not file formats (avi, vob, etc...). See library 'libavformat' for the
- * format handling
- */
-
-#include <stdlib.h>
-#include <stdio.h>
-#include <string.h>
-
-#ifdef HAVE_AV_CONFIG_H
-#undef HAVE_AV_CONFIG_H
-#endif
-
-#include "libavcodec/avcodec.h"
-#include "libavutil/audioconvert.h"
-#include "libavutil/mathematics.h"
-#include "libavutil/samplefmt.h"
-
-#define INBUF_SIZE 4096
-#define AUDIO_INBUF_SIZE 20480
-#define AUDIO_REFILL_THRESH 4096
-
-/* check that a given sample format is supported by the encoder */
-static int check_sample_fmt(AVCodec *codec, enum AVSampleFormat sample_fmt)
-{
- const enum AVSampleFormat *p = codec->sample_fmts;
-
- while (*p != AV_SAMPLE_FMT_NONE) {
- if (*p == sample_fmt)
- return 1;
- p++;
- }
- return 0;
-}
-
-/* just pick the highest supported samplerate */
-static int select_sample_rate(AVCodec *codec)
-{
- const int *p;
- int best_samplerate = 0;
-
- if (!codec->supported_samplerates)
- return 44100;
-
- p = codec->supported_samplerates;
- while (*p) {
- best_samplerate = FFMAX(*p, best_samplerate);
- p++;
- }
- return best_samplerate;
-}
-
-/* select layout with the highest channel count */
-static int select_channel_layout(AVCodec *codec)
-{
- const uint64_t *p;
- uint64_t best_ch_layout = 0;
- int best_nb_channells = 0;
-
- if (!codec->channel_layouts)
- return AV_CH_LAYOUT_STEREO;
-
- p = codec->channel_layouts;
- while (*p) {
- int nb_channels = av_get_channel_layout_nb_channels(*p);
-
- if (nb_channels > best_nb_channells) {
- best_ch_layout = *p;
- best_nb_channells = nb_channels;
- }
- p++;
- }
- return best_ch_layout;
-}
-
-/*
- * Audio encoding example
- */
-static void audio_encode_example(const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- AVFrame *frame;
- AVPacket pkt;
- int i, j, k, ret, got_output;
- int buffer_size;
- FILE *f;
- uint16_t *samples;
- float t, tincr;
-
- printf("Audio encoding\n");
-
- /* find the MP2 encoder */
- codec = avcodec_find_encoder(AV_CODEC_ID_MP2);
- if (!codec) {
- fprintf(stderr, "codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
-
- /* put sample parameters */
- c->bit_rate = 64000;
-
- /* check that the encoder supports s16 pcm input */
- c->sample_fmt = AV_SAMPLE_FMT_S16;
- if (!check_sample_fmt(codec, c->sample_fmt)) {
- fprintf(stderr, "encoder does not support %s",
- av_get_sample_fmt_name(c->sample_fmt));
- exit(1);
- }
-
- /* select other audio parameters supported by the encoder */
- c->sample_rate = select_sample_rate(codec);
- c->channel_layout = select_channel_layout(codec);
- c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "wb");
- if (!f) {
- fprintf(stderr, "could not open %s\n", filename);
- exit(1);
- }
-
- /* frame containing input raw audio */
- frame = avcodec_alloc_frame();
- if (!frame) {
- fprintf(stderr, "could not allocate audio frame\n");
- exit(1);
- }
-
- frame->nb_samples = c->frame_size;
- frame->format = c->sample_fmt;
- frame->channel_layout = c->channel_layout;
-
- /* the codec gives us the frame size, in samples,
- * we calculate the size of the samples buffer in bytes */
- buffer_size = av_samples_get_buffer_size(NULL, c->channels, c->frame_size,
- c->sample_fmt, 0);
- samples = av_malloc(buffer_size);
- if (!samples) {
- fprintf(stderr, "could not allocate %d bytes for samples buffer\n",
- buffer_size);
- exit(1);
- }
- /* setup the data pointers in the AVFrame */
- ret = avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt,
- (const uint8_t*)samples, buffer_size, 0);
- if (ret < 0) {
- fprintf(stderr, "could not setup audio frame\n");
- exit(1);
- }
-
- /* encode a single tone sound */
- t = 0;
- tincr = 2 * M_PI * 440.0 / c->sample_rate;
- for(i=0;i<200;i++) {
- av_init_packet(&pkt);
- pkt.data = NULL; // packet data will be allocated by the encoder
- pkt.size = 0;
-
- for (j = 0; j < c->frame_size; j++) {
- samples[2*j] = (int)(sin(t) * 10000);
-
- for (k = 1; k < c->channels; k++)
- samples[2*j + k] = samples[2*j];
- t += tincr;
- }
- /* encode the samples */
- ret = avcodec_encode_audio2(c, &pkt, frame, &got_output);
- if (ret < 0) {
- fprintf(stderr, "error encoding audio frame\n");
- exit(1);
- }
- if (got_output) {
- fwrite(pkt.data, 1, pkt.size, f);
- av_free_packet(&pkt);
- }
- }
- fclose(f);
-
- av_freep(&samples);
- av_freep(&frame);
- avcodec_close(c);
- av_free(c);
-}
-
-/*
- * Audio decoding.
- */
-static void audio_decode_example(const char *outfilename, const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- int len;
- FILE *f, *outfile;
- uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
- AVPacket avpkt;
- AVFrame *decoded_frame = NULL;
-
- av_init_packet(&avpkt);
-
- printf("Audio decoding\n");
-
- /* find the mpeg audio decoder */
- codec = avcodec_find_decoder(AV_CODEC_ID_MP2);
- if (!codec) {
- fprintf(stderr, "codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "rb");
- if (!f) {
- fprintf(stderr, "could not open %s\n", filename);
- exit(1);
- }
- outfile = fopen(outfilename, "wb");
- if (!outfile) {
- av_free(c);
- exit(1);
- }
-
- /* decode until eof */
- avpkt.data = inbuf;
- avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
-
- while (avpkt.size > 0) {
- int got_frame = 0;
-
- if (!decoded_frame) {
- if (!(decoded_frame = avcodec_alloc_frame())) {
- fprintf(stderr, "out of memory\n");
- exit(1);
- }
- } else
- avcodec_get_frame_defaults(decoded_frame);
-
- len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt);
- if (len < 0) {
- fprintf(stderr, "Error while decoding\n");
- exit(1);
- }
- if (got_frame) {
- /* if a frame has been decoded, output it */
- int data_size = av_samples_get_buffer_size(NULL, c->channels,
- decoded_frame->nb_samples,
- c->sample_fmt, 1);
- fwrite(decoded_frame->data[0], 1, data_size, outfile);
- }
- avpkt.size -= len;
- avpkt.data += len;
- if (avpkt.size < AUDIO_REFILL_THRESH) {
- /* Refill the input buffer, to avoid trying to decode
- * incomplete frames. Instead of this, one could also use
- * a parser, or use a proper container format through
- * libavformat. */
- memmove(inbuf, avpkt.data, avpkt.size);
- avpkt.data = inbuf;
- len = fread(avpkt.data + avpkt.size, 1,
- AUDIO_INBUF_SIZE - avpkt.size, f);
- if (len > 0)
- avpkt.size += len;
- }
- }
-
- fclose(outfile);
- fclose(f);
-
- avcodec_close(c);
- av_free(c);
- av_free(decoded_frame);
-}
-
-/*
- * Video encoding example
- */
-static void video_encode_example(const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- int i, out_size, size, x, y, outbuf_size;
- FILE *f;
- AVFrame *picture;
- uint8_t *outbuf, *picture_buf;
-
- printf("Video encoding\n");
-
- /* find the mpeg1 video encoder */
- codec = avcodec_find_encoder(AV_CODEC_ID_MPEG1VIDEO);
- if (!codec) {
- fprintf(stderr, "codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
- picture= avcodec_alloc_frame();
-
- /* put sample parameters */
- c->bit_rate = 400000;
- /* resolution must be a multiple of two */
- c->width = 352;
- c->height = 288;
- /* frames per second */
- c->time_base= (AVRational){1,25};
- c->gop_size = 10; /* emit one intra frame every ten frames */
- c->max_b_frames=1;
- c->pix_fmt = PIX_FMT_YUV420P;
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "wb");
- if (!f) {
- fprintf(stderr, "could not open %s\n", filename);
- exit(1);
- }
-
- /* alloc image and output buffer */
- outbuf_size = 100000;
- outbuf = malloc(outbuf_size);
- size = c->width * c->height;
- picture_buf = malloc((size * 3) / 2); /* size for YUV 420 */
-
- picture->data[0] = picture_buf;
- picture->data[1] = picture->data[0] + size;
- picture->data[2] = picture->data[1] + size / 4;
- picture->linesize[0] = c->width;
- picture->linesize[1] = c->width / 2;
- picture->linesize[2] = c->width / 2;
-
- /* encode 1 second of video */
- for(i=0;i<25;i++) {
- fflush(stdout);
- /* prepare a dummy image */
- /* Y */
- for(y=0;y<c->height;y++) {
- for(x=0;x<c->width;x++) {
- picture->data[0][y * picture->linesize[0] + x] = x + y + i * 3;
- }
- }
-
- /* Cb and Cr */
- for(y=0;y<c->height/2;y++) {
- for(x=0;x<c->width/2;x++) {
- picture->data[1][y * picture->linesize[1] + x] = 128 + y + i * 2;
- picture->data[2][y * picture->linesize[2] + x] = 64 + x + i * 5;
- }
- }
-
- /* encode the image */
- out_size = avcodec_encode_video(c, outbuf, outbuf_size, picture);
- printf("encoding frame %3d (size=%5d)\n", i, out_size);
- fwrite(outbuf, 1, out_size, f);
- }
-
- /* get the delayed frames */
- for(; out_size; i++) {
- fflush(stdout);
-
- out_size = avcodec_encode_video(c, outbuf, outbuf_size, NULL);
- printf("write frame %3d (size=%5d)\n", i, out_size);
- fwrite(outbuf, 1, out_size, f);
- }
-
- /* add sequence end code to have a real mpeg file */
- outbuf[0] = 0x00;
- outbuf[1] = 0x00;
- outbuf[2] = 0x01;
- outbuf[3] = 0xb7;
- fwrite(outbuf, 1, 4, f);
- fclose(f);
- free(picture_buf);
- free(outbuf);
-
- avcodec_close(c);
- av_free(c);
- av_free(picture);
- printf("\n");
-}
-
-/*
- * Video decoding example
- */
-
-static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
- char *filename)
-{
- FILE *f;
- int i;
-
- f=fopen(filename,"w");
- fprintf(f,"P5\n%d %d\n%d\n",xsize,ysize,255);
- for(i=0;i<ysize;i++)
- fwrite(buf + i * wrap,1,xsize,f);
- fclose(f);
-}
-
-static void video_decode_example(const char *outfilename, const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- int frame, got_picture, len;
- FILE *f;
- AVFrame *picture;
- uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
- char buf[1024];
- AVPacket avpkt;
-
- av_init_packet(&avpkt);
-
- /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
- memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
-
- printf("Video decoding\n");
-
- /* find the mpeg1 video decoder */
- codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO);
- if (!codec) {
- fprintf(stderr, "codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
- picture= avcodec_alloc_frame();
-
- if(codec->capabilities&CODEC_CAP_TRUNCATED)
- c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
-
- /* For some codecs, such as msmpeg4 and mpeg4, width and height
- MUST be initialized there because this information is not
- available in the bitstream. */
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "could not open codec\n");
- exit(1);
- }
-
- /* the codec gives us the frame size, in samples */
-
- f = fopen(filename, "rb");
- if (!f) {
- fprintf(stderr, "could not open %s\n", filename);
- exit(1);
- }
-
- frame = 0;
- for(;;) {
- avpkt.size = fread(inbuf, 1, INBUF_SIZE, f);
- if (avpkt.size == 0)
- break;
-
- /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
- and this is the only method to use them because you cannot
- know the compressed data size before analysing it.
-
- BUT some other codecs (msmpeg4, mpeg4) are inherently frame
- based, so you must call them with all the data for one
- frame exactly. You must also initialize 'width' and
- 'height' before initializing them. */
-
- /* NOTE2: some codecs allow the raw parameters (frame size,
- sample rate) to be changed at any frame. We handle this, so
- you should also take care of it */
-
- /* here, we use a stream based decoder (mpeg1video), so we
- feed decoder and see if it could decode a frame */
- avpkt.data = inbuf;
- while (avpkt.size > 0) {
- len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
- if (len < 0) {
- fprintf(stderr, "Error while decoding frame %d\n", frame);
- exit(1);
- }
- if (got_picture) {
- printf("saving frame %3d\n", frame);
- fflush(stdout);
-
- /* the picture is allocated by the decoder. no need to
- free it */
- snprintf(buf, sizeof(buf), outfilename, frame);
- pgm_save(picture->data[0], picture->linesize[0],
- c->width, c->height, buf);
- frame++;
- }
- avpkt.size -= len;
- avpkt.data += len;
- }
- }
-
- /* some codecs, such as MPEG, transmit the I and P frame with a
- latency of one frame. You must do the following to have a
- chance to get the last frame of the video */
- avpkt.data = NULL;
- avpkt.size = 0;
- len = avcodec_decode_video2(c, picture, &got_picture, &avpkt);
- if (got_picture) {
- printf("saving last frame %3d\n", frame);
- fflush(stdout);
-
- /* the picture is allocated by the decoder. no need to
- free it */
- snprintf(buf, sizeof(buf), outfilename, frame);
- pgm_save(picture->data[0], picture->linesize[0],
- c->width, c->height, buf);
- frame++;
- }
-
- fclose(f);
-
- avcodec_close(c);
- av_free(c);
- av_free(picture);
- printf("\n");
-}
-
-int main(int argc, char **argv)
-{
- const char *filename;
-
- /* register all the codecs */
- avcodec_register_all();
-
- if (argc <= 1) {
- audio_encode_example("/tmp/test.mp2");
- audio_decode_example("/tmp/test.sw", "/tmp/test.mp2");
-
- video_encode_example("/tmp/test.mpg");
- filename = "/tmp/test.mpg";
- } else {
- filename = argv[1];
- }
-
- // audio_decode_example("/tmp/test.sw", filename);
- video_decode_example("/tmp/test%d.pgm", filename);
-
- return 0;
-}
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