使用FFmpeg新解码API解封装解码音视频(代码实例)

2023-10-09 22:15:46

在ffmpeg的源代码中，有新旧版本的编解码接口调用示例，但是demux、mux然后decode、encode的联动起来的接口调用实例并没有，在使用旧版本的编解码接口在编译时会报接口弃用告警信息，所以最好尽快把原有的调用方式切换到新的编解码接口调用方式，告警信息如下：

点击(此处)折叠或打开

liuqideMBP:xxx liuqi$ make doc/examples/demuxing_decoding
CC doc/examples/demuxing_decoding.o
src/doc/examples/demuxing_decoding.c:73:15: warning: 'avcodec_decode_video2' is deprecated [-Wdeprecated-declarations]
ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt);
^
src/libavcodec/avcodec.h:4631:1: note: 'avcodec_decode_video2' has been explicitly marked deprecated here
attribute_deprecated
^
src/libavutil/attributes.h:94:49: note: expanded from macro 'attribute_deprecated'
# define attribute_deprecated __attribute__((deprecated))
^
src/doc/examples/demuxing_decoding.c:111:15: warning: 'avcodec_decode_audio4' is deprecated [-Wdeprecated-declarations]
ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame, &pkt);
^
src/libavcodec/avcodec.h:4582:1: note: 'avcodec_decode_audio4' has been explicitly marked deprecated here
attribute_deprecated
^
src/libavutil/attributes.h:94:49: note: expanded from macro 'attribute_deprecated'
# define attribute_deprecated __attribute__((deprecated))
^
2 warnings generated.
LD doc/examples/demuxing_decoding_g
ld: warning: directory not found for option '-Llibavresample'
STRIP doc/examples/demuxing_decoding

为了修改方便，而网上又没有只管举例的相关完整的实例，所以在这里写一个例子，供大伙参考

/*
* Copyright (c) 2017 bbs.chinaffmpeg.com 孙悟空
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/**
* @file
* Demuxing and decoding example.
*
* Show how to use the libavformat and libavcodec API to demux and
* decode audio and video data.
* @example demuxing_decoding.c
*/
#include libavutil/imgutils.h>
#include libavutil/samplefmt.h>
#include libavutil/timestamp.h>
#include libavformat/avformat.h>
static AVFormatContext *fmt_ctx = NULL;
static AVCodecContext *video_dec_ctx = NULL, *audio_dec_ctx;
static int width, height;
static enum AVPixelFormat pix_fmt;
static AVStream *video_stream = NULL, *audio_stream = NULL;
static const char *src_filename = NULL;
static const char *video_dst_filename = NULL;
static const char *audio_dst_filename = NULL;
static FILE *video_dst_file = NULL;
static FILE *audio_dst_file = NULL;
static uint8_t *video_dst_data[4] = {NULL};
static int video_dst_linesize[4];
static int video_dst_bufsize;
static int video_stream_idx = -1, audio_stream_idx = -1;
static AVFrame *frame = NULL;
static AVPacket pkt;
static int video_frame_count = 0;
static int audio_frame_count = 0;
/* Enable or disable frame reference counting. You are not supposed to support
* both paths in your application but pick the one most appropriate to your
* needs. Look for the use of refcount in this example to see what are the
* differences of API usage between them. */
static int refcount = 0;
static int decode_packet(int *got_frame, int cached)
{
int ret = 0;
int i = 0;
int ch = 0;
int data_size = 0;
int decoded = pkt.size;
*got_frame = 0;
if (pkt.stream_index == video_stream_idx) {
/* decode video frame */
ret = avcodec_send_packet(video_dec_ctx, &pkt);
if (ret 0) {
fprintf(stderr, "Error sending a packet for decoding\n");
exit(1);
}
while (ret >= 0) {
ret = avcodec_receive_frame(video_dec_ctx, frame);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
return ret;
else if (ret 0) {
fprintf(stderr, "Error during decoding\n");
exit(1);
}
printf("bbs.chinaffmpeg.com 孙悟空 video_frame%s n:%d coded_n:%d\n",
cached ? "(cached)" : "",
video_frame_count++, frame->coded_picture_number);
/* copy decoded frame to destination buffer:
* this is required since rawvideo expects non aligned data */
av_image_copy(video_dst_data, video_dst_linesize,
(const uint8_t **)(frame->data), frame->linesize,
pix_fmt, width, height);
/* write to rawvideo file */
fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);
printf("saving frame %3d\n", video_dec_ctx->frame_number);
fflush(stdout);
}
} else if (pkt.stream_index == audio_stream_idx) {
/* decode audio frame */
#if 1
/* send the packet with the compressed data to the decoder */
ret = avcodec_send_packet(audio_dec_ctx, &pkt);
if (ret 0) {
fprintf(stderr, "Error submitting the packet to the decoder\n");
exit(1);
}
/* read all the output frames (in general there may be any number of them */
while (ret >= 0) {
ret = avcodec_receive_frame(audio_dec_ctx, frame);
if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
return ret;
else if (ret 0) {
fprintf(stderr, "Error during decoding\n");
exit(1);
}
data_size = av_get_bytes_per_sample(audio_dec_ctx->sample_fmt);
if (data_size 0) {
/* This should not occur, checking just for paranoia */
fprintf(stderr, "Failed to calculate data size\n");
exit(1);
}
for (i = 0; i frame->nb_samples; i++)
for (ch = 0; ch audio_dec_ctx->channels; ch++)
fwrite(frame->data[ch] + data_size*i, 1, data_size, audio_dst_file);
}
printf("audio_frame%s n:%d nb_samples:%d pts:%s\n",
cached ? "(cached)" : "",
audio_frame_count++, frame->nb_samples,
av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));
#else
ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame, &pkt);
if (ret 0) {
fprintf(stderr, "Error decoding audio frame (%s)\n", av_err2str(ret));
return ret;
}
/* Some audio decoders decode only part of the packet, and have to be
* called again with the remainder of the packet data.
* Sample: 转自bbs.chinaffmpeg.com 孙悟空fate-suite/lossless-audio/
* luckynight-partial.shn
* Also, some decoders might over-read the packet. */
decoded = FFMIN(ret, pkt.size);
if (*got_frame) {
size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);
printf("audio_frame%s n:%d nb_samples:%d pts:%s\n",
cached ? "(cached)" : "",
audio_frame_count++, frame->nb_samples,
av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));
/* Write the raw audio data samples of the first plane. This works
* fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,
* most audio decoders output planar audio, which uses a separate
* plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).
* In other words, this code will write only the first audio channel
* in these cases.
* You should use libswresample or libavfilter to convert the frame
* to packed data. */
fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);
}
#endif
}
/* If we use frame reference counting, we own the data and need
* to de-reference it when we don't use it anymore */
if (*got_frame && refcount)
av_frame_unref(frame);
return decoded;
}
static int open_codec_context(int *stream_idx,
AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type)
{
int ret, stream_index;
AVStream *st;
AVCodec *dec = NULL;
AVDictionary *opts = NULL;
ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
if (ret 0) {
fprintf(stderr, "Could not find %s stream in input file '%s'\n",
av_get_media_type_string(type), src_filename);
return ret;
} else {
stream_index = ret;
st = fmt_ctx->streams[stream_index];
/* find decoder for the stream */
dec = avcodec_find_decoder(st->codecpar->codec_id);
if (!dec) {
fprintf(stderr, "Failed to find %s codec\n",
av_get_media_type_string(type));
return AVERROR(EINVAL);
}
/* Allocate a codec context for the decoder */
*dec_ctx = avcodec_alloc_context3(dec);
if (!*dec_ctx) {
fprintf(stderr, "Failed to allocate the %s codec context\n",
av_get_media_type_string(type));
return AVERROR(ENOMEM);
}
/* Copy codec parameters from input stream to output codec context */
if ((ret = avcodec_parameters_to_context(*dec_ctx, st->codecpar)) 0) {
fprintf(stderr, "Failed to copy %s codec parameters to decoder context\n",
av_get_media_type_string(type));
return ret;
}
/* Init the decoders, with or without reference counting */
av_dict_set(&opts, "refcounted_frames", refcount ? "1" : "0", 0);
if ((ret = avcodec_open2(*dec_ctx, dec, &opts)) 0) {
fprintf(stderr, "Failed to open %s codec\n",
av_get_media_type_string(type));
return ret;
}
*stream_idx = stream_index;
}
return 0;
}
static int get_format_from_sample_fmt(const char **fmt,
enum AVSampleFormat sample_fmt)
{
int i;
struct sample_fmt_entry {
enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;
} sample_fmt_entries[] = {
{ AV_SAMPLE_FMT_U8, "u8", "u8" },
{ AV_SAMPLE_FMT_S16, "s16be", "s16le" },
{ AV_SAMPLE_FMT_S32, "s32be", "s32le" },
{ AV_SAMPLE_FMT_FLT, "f32be", "f32le" },
{ AV_SAMPLE_FMT_DBL, "f64be", "f64le" },
};
*fmt = NULL;
for (i = 0; i FF_ARRAY_ELEMS(sample_fmt_entries); i++) {
struct sample_fmt_entry *entry = &sample_fmt_entries[i];
if (sample_fmt == entry->sample_fmt) {
*fmt = AV_NE(entry->fmt_be, entry->fmt_le);
return 0;
}
}
fprintf(stderr,
"sample format %s is not supported as output format\n",
av_get_sample_fmt_name(sample_fmt));
return -1;
}
int main (int argc, char **argv)
{
int ret = 0, got_frame;
if (argc != 4 && argc != 5) {
fprintf(stderr, "usage: %s [-refcount] input_file video_output_file audio_output_file\n"
"API example program to show how to read frames from an input file.\n"
"This program reads frames from a file, decodes them, and writes decoded\n"
"video frames to a rawvideo file named video_output_file, and decoded\n"
"audio frames to a rawaudio file named audio_output_file.\n\n"
"If the -refcount option is specified, the program use the\n"
"reference counting frame system which allows keeping a copy of\n"
"the data for longer than one decode call.\n"
"\n", argv[0]);
exit(1);
}
if (argc == 5 && !strcmp(argv[1], "-refcount")) {
refcount = 1;
argv++;
}
src_filename = argv[1];
video_dst_filename = argv[2];
audio_dst_filename = argv[3];
/* register all formats and codecs */
av_register_all();
/* open input file, and allocate format context */
if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) 0) {
fprintf(stderr, "Could not open source file %s\n", src_filename);
exit(1);
}
/* retrieve stream information */
if (avformat_find_stream_info(fmt_ctx, NULL) 0) {
fprintf(stderr, "Could not find stream information\n");
exit(1);
}
if (open_codec_context(&video_stream_idx, &video_dec_ctx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) {
video_stream = fmt_ctx->streams[video_stream_idx];
video_dst_file = fopen(video_dst_filename, "wb");
if (!video_dst_file) {
fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);
ret = 1;
goto end;
}
/* allocate image where the decoded image will be put */
width = video_dec_ctx->width;
height = video_dec_ctx->height;
pix_fmt = video_dec_ctx->pix_fmt;
ret = av_image_alloc(video_dst_data, video_dst_linesize,
width, height, pix_fmt, 1);
if (ret 0) {
fprintf(stderr, "Could not allocate raw video buffer\n");
goto end;
}
video_dst_bufsize = ret;
}
if (open_codec_context(&audio_stream_idx, &audio_dec_ctx, fmt_ctx, AVMEDIA_TYPE_AUDIO) >= 0) {
audio_stream = fmt_ctx->streams[audio_stream_idx];
audio_dst_file = fopen(audio_dst_filename, "wb");
if (!audio_dst_file) {
fprintf(stderr, "Could not open destination file %s\n", audio_dst_filename);
ret = 1;
goto end;
}
}
/* dump input information to stderr */
av_dump_format(fmt_ctx, 0, src_filename, 0);
if (!audio_stream && !video_stream) {
fprintf(stderr, "Could not find audio or video stream in the input, aborting\n");
ret = 1;
goto end;
}
frame = av_frame_alloc();
if (!frame) {
fprintf(stderr, "Could not allocate frame\n");
ret = AVERROR(ENOMEM);
goto end;
}
/* initialize packet, set data to NULL, let the demuxer fill it */
av_init_packet(&pkt);
pkt.data = NULL;
pkt.size = 0;
if (video_stream)
printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);
if (audio_stream)
printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);
/* read frames from the file */
while (av_read_frame(fmt_ctx, &pkt) >= 0) {
AVPacket orig_pkt = pkt;
do {
ret = decode_packet(&got_frame, 0);
if (ret 0)
break;
pkt.data += ret;
pkt.size -= ret;
} while (pkt.size > 0);
av_packet_unref(&orig_pkt);
}
/* flush cached frames */
pkt.data = NULL;
pkt.size = 0;
do {
decode_packet(&got_frame, 1);
} while (got_frame);
printf("Demuxing succeeded.\n");
if (video_stream) {
printf("Play the output video file with the command:\n"
"ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
av_get_pix_fmt_name(pix_fmt), width, height,
video_dst_filename);
}
if (audio_stream) {
enum AVSampleFormat sfmt = audio_dec_ctx->sample_fmt;
int n_channels = audio_dec_ctx->channels;
const char *fmt;
if (av_sample_fmt_is_planar(sfmt)) {
const char *packed = av_get_sample_fmt_name(sfmt);
printf("Warning: the sample format the decoder produced is planar "
"(%s). This example will output the first channel only.\n",
packed ? packed : "?");
sfmt = av_get_packed_sample_fmt(sfmt);
n_channels = 2;
}
if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) 0)
goto end;
printf("Play the output audio file with the command:\n"
"ffplay -f %s -ac %d -ar %d %s\n",
fmt, n_channels, audio_dec_ctx->sample_rate,
audio_dst_filename);
}
end:
avcodec_free_context(&video_dec_ctx);
avcodec_free_context(&audio_dec_ctx);
avformat_close_input(&fmt_ctx);
if (video_dst_file)
fclose(video_dst_file);
if (audio_dst_file)
fclose(audio_dst_file);
av_frame_free(&frame);
av_free(video_dst_data[0]);
return ret 0;
}

下面看一下编译的方式，其实我是用的ffmpeg原生的编译方式编译的make doc/examples/demuxing_decoding，在这里贴一下make -n doc/examples/demuxing_decoding的输出

点击(此处)折叠或打开

liuqideMBP:xxx liuqi$ make -n doc/examples/demuxing_decoding
printf "CC\t%s\n" doc/examples/demuxing_decoding.o; ccache gcc -I. -Isrc/ -D_ISOC99_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -I/Users/liuqi/multimedia/ffmpeg/compat/dispatch_semaphore -DPIC -DZLIB_CONST -std=c11 -Werror=partial-availability -fomit-frame-pointer -fPIC -pthread -I/usr/local/include -I/usr/local/Cellar/fontconfig/2.12.6/include -I/usr/local/opt/freetype/include/freetype2 -I/usr/local/Cellar/fribidi/0.19.7_1/include/fribidi -I/usr/local/Cellar/glib/2.54.2/include/glib-2.0 -I/usr/local/Cellar/glib/2.54.2/lib/glib-2.0/include -I/usr/local/opt/gettext/include -I/usr/local/Cellar/pcre/8.41/include -I/usr/local/opt/freetype/include/freetype2 -I/usr/local/Cellar/libbluray/1.0.1/include -I/usr/local/include -I/usr/local/Cellar/fontconfig/2.12.6/include -I/usr/local/opt/freetype/include/freetype2 -I/usr/local/opt/freetype/include/freetype2 -I/usr/local/Cellar/speex/1.2rc1/include -I/usr/local/include -I/usr/local/Cellar/x265/2.5_1/include -g -Wdeclaration-after-statement -Wall -Wdisabled-optimization -Wpointer-arith -Wredundant-decls -Wwrite-strings -Wtype-limits -Wundef -Wmissing-prototypes -Wno-pointer-to-int-cast -Wstrict-prototypes -Wempty-body -Wno-parentheses -Wno-switch -Wno-format-zero-length -Wno-pointer-sign -Wno-unused-const-variable -O3 -fno-math-errno -fno-signed-zeros -mstack-alignment=16 -Qunused-arguments -Werror=implicit-function-declaration -Werror=missing-prototypes -Werror=return-type -D_THREAD_SAFE -I/usr/local/include/SDL2 -MMD -MF doc/examples/demuxing_decoding.d -MT doc/examples/demuxing_decoding.o -c -o doc/examples/demuxing_decoding.o src/doc/examples/demuxing_decoding.c
printf "LD\t%s\n" doc/examples/demuxing_decoding_g; ccache gcc -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,-dynamic,-search_paths_first -Qunused-arguments -o doc/examples/demuxing_decoding_g doc/examples/demuxing_decoding.o -lavdevice -lavfilter -lavformat -lavcodec -lpostproc -lswresample -lswscale -lavutil -framework Foundation -lm -framework AVFoundation -framework CoreVideo -framework CoreMedia -pthread -framework CoreGraphics -L/usr/local/lib -lSDL2 -framework OpenGL -framework OpenGL -pthread -lm -L/usr/local/lib -lass -framework CoreImage -framework AppKit -L/usr/local/Cellar/fontconfig/2.12.6/lib -L/usr/local/opt/freetype/lib -lfontconfig -lfreetype -L/usr/local/opt/freetype/lib -lfreetype -lm -lbz2 -L/usr/local/Cellar/libbluray/1.0.1/lib -lbluray -lz -Wl,-framework,CoreFoundation -Wl,-framework,Security -liconv -lm -llzma -lz -framework AudioToolbox -L/usr/local/lib -lfdk-aac -lmp3lame -L/usr/local/Cellar/speex/1.2rc1/lib -lspeex -L/usr/local/lib -lx264 -L/usr/local/Cellar/x265/2.5_1/lib -lx265 -pthread -framework VideoToolbox -framework CoreFoundation -framework CoreMedia -framework CoreVideo -framework CoreServices -lm -lm -lm -pthread -lm -framework VideoToolbox -framework CoreFoundation -framework CoreMedia -framework CoreVideo -framework CoreServices
printf "STRIP\t%s\n" doc/examples/demuxing_decoding; strip -x -o doc/examples/demuxing_decoding doc/examples/demuxing_decoding_g

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