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author | Clément Bœsch <clement@stupeflix.com> | 2013-11-04 12:35:17 +0100 |
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committer | Clément Bœsch <clement@stupeflix.com> | 2013-11-04 12:53:06 +0100 |
commit | fb10b43fc42b278c856eb98df524048500648ea4 (patch) | |
tree | 8883df16a330eb3009310e408d9e95c340e1c84c /doc/examples/demuxing.c | |
parent | d10b1a200dc3676f014f7e2c020800a15c7cab8a (diff) | |
download | ffmpeg-fb10b43fc42b278c856eb98df524048500648ea4.tar.gz |
doc/examples: rename demuxing to demuxing_decoding.
That example shows how the decoding process works, not only the
demuxing.
Diffstat (limited to 'doc/examples/demuxing.c')
-rw-r--r-- | doc/examples/demuxing.c | 388 |
1 files changed, 0 insertions, 388 deletions
diff --git a/doc/examples/demuxing.c b/doc/examples/demuxing.c deleted file mode 100644 index b13246e2a4..0000000000 --- a/doc/examples/demuxing.c +++ /dev/null @@ -1,388 +0,0 @@ -/* - * Copyright (c) 2012 Stefano Sabatini - * - * 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 - * libavformat demuxing API use example. - * - * Show how to use the libavformat and libavcodec API to demux and - * decode audio and video data. - * @example doc/examples/demuxing.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 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; - -/* The different ways of decoding and managing data memory. You are not - * supposed to support all the modes in your application but pick the one most - * appropriate to your needs. Look for the use of api_mode in this example to - * see what are the differences of API usage between them */ -enum { - API_MODE_OLD = 0, /* old method, deprecated */ - API_MODE_NEW_API_REF_COUNT = 1, /* new method, using the frame reference counting */ - API_MODE_NEW_API_NO_REF_COUNT = 2, /* new method, without reference counting */ -}; - -static int api_mode = API_MODE_OLD; - -static int decode_packet(int *got_frame, int cached) -{ - int ret = 0; - int decoded = pkt.size; - - *got_frame = 0; - - if (pkt.stream_index == video_stream_idx) { - /* decode video frame */ - ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt); - if (ret < 0) { - fprintf(stderr, "Error decoding video frame\n"); - return ret; - } - - if (*got_frame) { - printf("video_frame%s n:%d coded_n:%d pts:%s\n", - cached ? "(cached)" : "", - video_frame_count++, frame->coded_picture_number, - av_ts2timestr(frame->pts, &video_dec_ctx->time_base)); - - /* 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, - video_dec_ctx->pix_fmt, video_dec_ctx->width, video_dec_ctx->height); - - /* write to rawvideo file */ - fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file); - } - } else if (pkt.stream_index == audio_stream_idx) { - /* decode audio frame */ - ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame, &pkt); - if (ret < 0) { - fprintf(stderr, "Error decoding audio frame\n"); - 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: 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); - } - } - - /* If we use the new API with reference counting, we own the data and need - * to de-reference it when we don't use it anymore */ - if (*got_frame && api_mode == API_MODE_NEW_API_REF_COUNT) - av_frame_unref(frame); - - return decoded; -} - -static int open_codec_context(int *stream_idx, - AVFormatContext *fmt_ctx, enum AVMediaType type) -{ - int ret; - AVStream *st; - AVCodecContext *dec_ctx = NULL; - 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_idx = ret; - st = fmt_ctx->streams[*stream_idx]; - - /* find decoder for the stream */ - dec_ctx = st->codec; - dec = avcodec_find_decoder(dec_ctx->codec_id); - if (!dec) { - fprintf(stderr, "Failed to find %s codec\n", - av_get_media_type_string(type)); - return ret; - } - - /* Init the decoders, with or without reference counting */ - if (api_mode == API_MODE_NEW_API_REF_COUNT) - av_dict_set(&opts, "refcounted_frames", "1", 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; - } - } - - 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=<old|new_norefcount|new_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. If unset, it's using\n" - "the classic old method.\n" - "\n", argv[0]); - exit(1); - } - if (argc == 5) { - const char *mode = argv[1] + strlen("-refcount="); - if (!strcmp(mode, "old")) api_mode = API_MODE_OLD; - else if (!strcmp(mode, "new_norefcount")) api_mode = API_MODE_NEW_API_NO_REF_COUNT; - else if (!strcmp(mode, "new_refcount")) api_mode = API_MODE_NEW_API_REF_COUNT; - else { - fprintf(stderr, "unknow mode '%s'\n", mode); - exit(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, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) { - video_stream = fmt_ctx->streams[video_stream_idx]; - video_dec_ctx = video_stream->codec; - - 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 */ - ret = av_image_alloc(video_dst_data, video_dst_linesize, - video_dec_ctx->width, video_dec_ctx->height, - video_dec_ctx->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, fmt_ctx, AVMEDIA_TYPE_AUDIO) >= 0) { - audio_stream = fmt_ctx->streams[audio_stream_idx]; - audio_dec_ctx = audio_stream->codec; - audio_dst_file = fopen(audio_dst_filename, "wb"); - if (!audio_dst_file) { - fprintf(stderr, "Could not open destination file %s\n", video_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; - } - - /* When using the new API, you need to use the libavutil/frame.h API, while - * the classic frame management is available in libavcodec */ - if (api_mode == API_MODE_OLD) - frame = avcodec_alloc_frame(); - else - 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_free_packet(&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(video_dec_ctx->pix_fmt), video_dec_ctx->width, video_dec_ctx->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 = 1; - } - - 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: - if (video_dec_ctx) - avcodec_close(video_dec_ctx); - if (audio_dec_ctx) - avcodec_close(audio_dec_ctx); - avformat_close_input(&fmt_ctx); - if (video_dst_file) - fclose(video_dst_file); - if (audio_dst_file) - fclose(audio_dst_file); - if (api_mode == API_MODE_OLD) - avcodec_free_frame(&frame); - else - av_frame_free(&frame); - av_free(video_dst_data[0]); - - return ret < 0; -} |