Function decode_audio_specific_config

libavcodec/aacdec.c:462–493

* Decode audio specific configuration; reference: table 1.13. * * @param data pointer to AVCodecContext extradata * @param data_size size of AVCCodecContext extradata * * @return Returns error status. 0 - OK, !0 - error */

 * @return  Returns error status. 0 - OK, !0 - error
 */
static int decode_audio_specific_config(AACContext *ac, void *data,
                                        int data_size)
{
    GetBitContext gb;
    int i;

    init_get_bits(&gb, data, data_size * 8);

    if ((i = ff_mpeg4audio_get_config(&ac->m4ac, data, data_size)) < 0)
        return -1;
    if (ac->m4ac.sampling_index > 12) {
        av_log(ac->avctx, AV_LOG_ERROR, "invalid sampling rate index %d\n", ac->m4ac.sampling_index);
        return -1;
    }
    if (ac->m4ac.sbr == 1 && ac->m4ac.ps == -1)
        ac->m4ac.ps = 1;

    skip_bits_long(&gb, i);

    switch (ac->m4ac.object_type) {
    case AOT_AAC_MAIN:
    case AOT_AAC_LC:
        if (decode_ga_specific_config(ac, &gb, ac->m4ac.chan_config))
            return -1;
        break;
    default:
        av_log(ac->avctx, AV_LOG_ERROR, "Audio object type %s%d is not supported.\n",
               ac->m4ac.sbr == 1? "SBR+" : "", ac->m4ac.object_type);
        return -1;
    }
    return 0;
}

/**
 * linear congruential pseudorandom number generator