diff --git a/doc/examples/demuxing_decoding.c b/doc/examples/demuxing_decoding.c index 59e0ccc986..49fb6afae1 100644 --- a/doc/examples/demuxing_decoding.c +++ b/doc/examples/demuxing_decoding.c @@ -148,11 +148,10 @@ static int decode_packet(int *got_frame, int cached) } static int open_codec_context(int *stream_idx, - AVFormatContext *fmt_ctx, enum AVMediaType type) + AVCodecContext **dec_ctx, AVFormatContext *fmt_ctx, enum AVMediaType type) { int ret, stream_index; AVStream *st; - AVCodecContext *dec_ctx = NULL; AVCodec *dec = NULL; AVDictionary *opts = NULL; @@ -166,17 +165,31 @@ static int open_codec_context(int *stream_idx, st = fmt_ctx->streams[stream_index]; /* find decoder for the stream */ - dec_ctx = st->codec; - dec = avcodec_find_decoder(dec_ctx->codec_id); + 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) { + 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; @@ -255,9 +268,8 @@ int main (int argc, char **argv) exit(1); } - if (open_codec_context(&video_stream_idx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) { + 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_dec_ctx = video_stream->codec; video_dst_file = fopen(video_dst_filename, "wb"); if (!video_dst_file) { @@ -279,9 +291,8 @@ int main (int argc, char **argv) video_dst_bufsize = ret; } - if (open_codec_context(&audio_stream_idx, fmt_ctx, AVMEDIA_TYPE_AUDIO) >= 0) { + 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_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", audio_dst_filename); @@ -369,8 +380,8 @@ int main (int argc, char **argv) } end: - avcodec_close(video_dec_ctx); - avcodec_close(audio_dec_ctx); + 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);