Function stream_component_open

fftools/ffplay.c:2688–2846

open a given stream. Return 0 if OK */

/* open a given stream. Return 0 if OK */
static int stream_component_open(VideoState *is, int stream_index)
{
    AVFormatContext *ic = is->ic;
    AVCodecContext *avctx;
    const AVCodec *codec;
    const char *forced_codec_name = NULL;
    AVDictionary *opts = NULL;
    int sample_rate;
    AVChannelLayout ch_layout = { 0 };
    int ret = 0;
    int stream_lowres = lowres;

    if (stream_index < 0 || stream_index >= ic->nb_streams)
        return -1;

    avctx = avcodec_alloc_context3(NULL);
    if (!avctx)
        return AVERROR(ENOMEM);

    ret = avcodec_parameters_to_context(avctx, ic->streams[stream_index]->codecpar);
    if (ret < 0)
        goto fail;
    avctx->pkt_timebase = ic->streams[stream_index]->time_base;

    codec = avcodec_find_decoder(avctx->codec_id);

    switch(avctx->codec_type){
        case AVMEDIA_TYPE_AUDIO   : is->last_audio_stream    = stream_index; forced_codec_name =    audio_codec_name; break;
        case AVMEDIA_TYPE_SUBTITLE: is->last_subtitle_stream = stream_index; forced_codec_name = subtitle_codec_name; break;
        case AVMEDIA_TYPE_VIDEO   : is->last_video_stream    = stream_index; forced_codec_name =    video_codec_name; break;
    }
    if (forced_codec_name)
        codec = avcodec_find_decoder_by_name(forced_codec_name);
    if (!codec) {
        if (forced_codec_name) av_log(NULL, AV_LOG_WARNING,
                                      "No codec could be found with name '%s'\n", forced_codec_name);
        else                   av_log(NULL, AV_LOG_WARNING,
                                      "No decoder could be found for codec %s\n", avcodec_get_name(avctx->codec_id));
        ret = AVERROR(EINVAL);
        goto fail;
    }

    avctx->codec_id = codec->id;
    if (stream_lowres > codec->max_lowres) {
        av_log(avctx, AV_LOG_WARNING, "The maximum value for lowres supported by the decoder is %d\n",
                codec->max_lowres);
        stream_lowres = codec->max_lowres;
    }
    avctx->lowres = stream_lowres;

    if (fast)
        avctx->flags2 |= AV_CODEC_FLAG2_FAST;

    ret = filter_codec_opts(codec_opts, avctx->codec_id, ic,
                            ic->streams[stream_index], codec, &opts, NULL);
    if (ret < 0)
        goto fail;