ce70f28a17
`av_packet_unref` matches the AVFrame ref-counted API and can be used as a drop in replacement. Deprecate `av_free_packet`.
596 lines
16 KiB
C
596 lines
16 KiB
C
/*
|
|
* 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 avcodec.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/channel_layout.h"
|
|
#include "libavutil/common.h"
|
|
#include "libavutil/imgutils.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_channels = 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_channels) {
|
|
best_ch_layout = *p;
|
|
best_nb_channels = 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 = av_frame_alloc();
|
|
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_packet_unref(&pkt);
|
|
}
|
|
}
|
|
fclose(f);
|
|
|
|
av_freep(&samples);
|
|
av_frame_free(&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 + AV_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 = av_frame_alloc())) {
|
|
fprintf(stderr, "out of memory\n");
|
|
exit(1);
|
|
}
|
|
}
|
|
|
|
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_frame_free(&decoded_frame);
|
|
}
|
|
|
|
/*
|
|
* Video encoding example
|
|
*/
|
|
static void video_encode_example(const char *filename)
|
|
{
|
|
AVCodec *codec;
|
|
AVCodecContext *c= NULL;
|
|
int i, ret, x, y, got_output;
|
|
FILE *f;
|
|
AVFrame *picture;
|
|
AVPacket pkt;
|
|
uint8_t endcode[] = { 0, 0, 1, 0xb7 };
|
|
|
|
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 = av_frame_alloc();
|
|
|
|
/* 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 = AV_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);
|
|
}
|
|
|
|
ret = av_image_alloc(picture->data, picture->linesize, c->width, c->height,
|
|
c->pix_fmt, 32);
|
|
if (ret < 0) {
|
|
fprintf(stderr, "could not alloc raw picture buffer\n");
|
|
exit(1);
|
|
}
|
|
picture->format = c->pix_fmt;
|
|
picture->width = c->width;
|
|
picture->height = c->height;
|
|
|
|
/* encode 1 second of video */
|
|
for(i=0;i<25;i++) {
|
|
av_init_packet(&pkt);
|
|
pkt.data = NULL; // packet data will be allocated by the encoder
|
|
pkt.size = 0;
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
picture->pts = i;
|
|
|
|
/* encode the image */
|
|
ret = avcodec_encode_video2(c, &pkt, picture, &got_output);
|
|
if (ret < 0) {
|
|
fprintf(stderr, "error encoding frame\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (got_output) {
|
|
printf("encoding frame %3d (size=%5d)\n", i, pkt.size);
|
|
fwrite(pkt.data, 1, pkt.size, f);
|
|
av_packet_unref(&pkt);
|
|
}
|
|
}
|
|
|
|
/* get the delayed frames */
|
|
for (got_output = 1; got_output; i++) {
|
|
fflush(stdout);
|
|
|
|
ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);
|
|
if (ret < 0) {
|
|
fprintf(stderr, "error encoding frame\n");
|
|
exit(1);
|
|
}
|
|
|
|
if (got_output) {
|
|
printf("encoding frame %3d (size=%5d)\n", i, pkt.size);
|
|
fwrite(pkt.data, 1, pkt.size, f);
|
|
av_packet_unref(&pkt);
|
|
}
|
|
}
|
|
|
|
/* add sequence end code to have a real mpeg file */
|
|
fwrite(endcode, 1, sizeof(endcode), f);
|
|
fclose(f);
|
|
|
|
avcodec_close(c);
|
|
av_free(c);
|
|
av_freep(&picture->data[0]);
|
|
av_frame_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 + AV_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, AV_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 = av_frame_alloc();
|
|
|
|
if (codec->capabilities & AV_CODEC_CAP_TRUNCATED)
|
|
c->flags |= AV_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_frame_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;
|
|
}
|