diff options
author | Stefano Sabatini <[email protected]> | 2023-01-15 03:13:01 +0100 |
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committer | Stefano Sabatini <[email protected]> | 2023-02-11 17:49:01 +0100 |
commit | 7f5630a89983ac4f156ad643c0c8c42400e8102b (patch) | |
tree | df8a72c6f0f4f9204d76d1ce6cbc6024037c431f /doc/examples/demuxing_decoding.c | |
parent | f0a415c7eb47d4a71c93948f564d91d812070f6a (diff) |
examples: rename demuxing_decoding to demux_decode
Follow general scheme VERB_OBJECT.
Diffstat (limited to 'doc/examples/demuxing_decoding.c')
-rw-r--r-- | doc/examples/demuxing_decoding.c | 382 |
1 files changed, 0 insertions, 382 deletions
diff --git a/doc/examples/demuxing_decoding.c b/doc/examples/demuxing_decoding.c deleted file mode 100644 index 999a78db0d..0000000000 --- a/doc/examples/demuxing_decoding.c +++ /dev/null @@ -1,382 +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 - * 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 <libavcodec/avcodec.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 = NULL; -static int video_frame_count = 0; -static int audio_frame_count = 0; - -static int output_video_frame(AVFrame *frame) -{ - if (frame->width != width || frame->height != height || - frame->format != pix_fmt) { - /* To handle this change, one could call av_image_alloc again and - * decode the following frames into another rawvideo file. */ - fprintf(stderr, "Error: Width, height and pixel format have to be " - "constant in a rawvideo file, but the width, height or " - "pixel format of the input video changed:\n" - "old: width = %d, height = %d, format = %s\n" - "new: width = %d, height = %d, format = %s\n", - width, height, av_get_pix_fmt_name(pix_fmt), - frame->width, frame->height, - av_get_pix_fmt_name(frame->format)); - return -1; - } - - printf("video_frame n:%d coded_n:%d\n", - 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); - return 0; -} - -static int output_audio_frame(AVFrame *frame) -{ - size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format); - printf("audio_frame n:%d nb_samples:%d pts:%s\n", - 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); - - return 0; -} - -static int decode_packet(AVCodecContext *dec, const AVPacket *pkt) -{ - int ret = 0; - - // submit the packet to the decoder - ret = avcodec_send_packet(dec, pkt); - if (ret < 0) { - fprintf(stderr, "Error submitting a packet for decoding (%s)\n", av_err2str(ret)); - return ret; - } - - // get all the available frames from the decoder - while (ret >= 0) { - ret = avcodec_receive_frame(dec, frame); - if (ret < 0) { - // those two return values are special and mean there is no output - // frame available, but there were no errors during decoding - if (ret == AVERROR_EOF || ret == AVERROR(EAGAIN)) - return 0; - - fprintf(stderr, "Error during decoding (%s)\n", av_err2str(ret)); - return ret; - } - - // write the frame data to output file - if (dec->codec->type == AVMEDIA_TYPE_VIDEO) - ret = output_video_frame(frame); - else - ret = output_audio_frame(frame); - - av_frame_unref(frame); - if (ret < 0) - return ret; - } - - return 0; -} - -static int open_codec_context(int *stream_idx, - AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type) -{ - int ret, stream_index; - AVStream *st; - const AVCodec *dec = 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 */ - if ((ret = avcodec_open2(*dec_ctx, dec, NULL)) < 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; - - if (argc != 4) { - fprintf(stderr, "usage: %s 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", - argv[0]); - exit(1); - } - src_filename = argv[1]; - video_dst_filename = argv[2]; - audio_dst_filename = argv[3]; - - /* 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; - } - - pkt = av_packet_alloc(); - if (!pkt) { - fprintf(stderr, "Could not allocate packet\n"); - ret = AVERROR(ENOMEM); - goto end; - } - - 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) { - // check if the packet belongs to a stream we are interested in, otherwise - // skip it - if (pkt->stream_index == video_stream_idx) - ret = decode_packet(video_dec_ctx, pkt); - else if (pkt->stream_index == audio_stream_idx) - ret = decode_packet(audio_dec_ctx, pkt); - av_packet_unref(pkt); - if (ret < 0) - break; - } - - /* flush the decoders */ - if (video_dec_ctx) - decode_packet(video_dec_ctx, NULL); - if (audio_dec_ctx) - decode_packet(audio_dec_ctx, NULL); - - 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->ch_layout.nb_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: - 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_packet_free(&pkt); - av_frame_free(&frame); - av_free(video_dst_data[0]); - - return ret < 0; -} |