static int aac_decode_frame(AVCodecContext *avctx, void *data,
                            int *got_frame_ptr, AVPacket *avpkt)
{
    AACContext *ac = avctx->priv_data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    GetBitContext gb;
    int buf_consumed;
    int buf_offset;
    int err;
    int new_extradata_size;
    const uint8_t *new_extradata = av_packet_get_side_data(avpkt,
                                       AV_PKT_DATA_NEW_EXTRADATA,
                                       &new_extradata_size);
    int jp_dualmono_size;
    const uint8_t *jp_dualmono   = av_packet_get_side_data(avpkt,
                                       AV_PKT_DATA_JP_DUALMONO,
                                       &jp_dualmono_size);

    if (new_extradata && 0) {
        av_free(avctx->extradata);
        avctx->extradata = av_mallocz(new_extradata_size +
                                      FF_INPUT_BUFFER_PADDING_SIZE);
        if (!avctx->extradata)
            return AVERROR(ENOMEM);
        avctx->extradata_size = new_extradata_size;
        memcpy(avctx->extradata, new_extradata, new_extradata_size);
        push_output_configuration(ac);
        if (decode_audio_specific_config(ac, ac->avctx, &ac->oc[1].m4ac,
                                         avctx->extradata,
                                         avctx->extradata_size*8, 1) < 0) {
            pop_output_configuration(ac);
            return AVERROR_INVALIDDATA;
        }
    }

    ac->dmono_mode = 0;
    if (jp_dualmono && jp_dualmono_size > 0)
        ac->dmono_mode =  1 + *jp_dualmono;
    if (ac->force_dmono_mode >= 0)
        ac->dmono_mode = ac->force_dmono_mode;

    if (INT_MAX / 8 <= buf_size)
        return AVERROR_INVALIDDATA;

    if ((err = init_get_bits(&gb, buf, buf_size * 8)) < 0)
        return err;

    switch (ac->oc[1].m4ac.object_type) {
    case AOT_ER_AAC_LC:
    case AOT_ER_AAC_LTP:
    case AOT_ER_AAC_LD:
    case AOT_ER_AAC_ELD:
        err = aac_decode_er_frame(avctx, data, got_frame_ptr, &gb);
        break;
    default:
        err = aac_decode_frame_int(avctx, data, got_frame_ptr, &gb, avpkt);
    }
    if (err < 0)
        return err;

    buf_consumed = (get_bits_count(&gb) + 7) >> 3;
    for (buf_offset = buf_consumed; buf_offset < buf_size; buf_offset++)
        if (buf[buf_offset])
            break;

    return buf_size > buf_offset ? buf_consumed : buf_size;
}
Unknown