static av_cold int twin_decode_init(AVCodecContext *avctx) { int ret; TwinContext *tctx = avctx->priv_data; int isampf, ibps; tctx->avctx = avctx; avctx->sample_fmt = AV_SAMPLE_FMT_FLTP; if (!avctx->extradata || avctx->extradata_size < 12) { av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n"); return AVERROR_INVALIDDATA; } avctx->channels = AV_RB32(avctx->extradata ) + 1; avctx->bit_rate = AV_RB32(avctx->extradata + 4) * 1000; isampf = AV_RB32(avctx->extradata + 8); if (isampf < 8 || isampf > 44) { av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate\n"); return AVERROR_INVALIDDATA; } switch (isampf) { case 44: avctx->sample_rate = 44100; break; case 22: avctx->sample_rate = 22050; break; case 11: avctx->sample_rate = 11025; break; default: avctx->sample_rate = isampf * 1000; break; } if (avctx->channels <= 0 || avctx->channels > CHANNELS_MAX) { av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n", avctx->channels); return -1; } avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO : AV_CH_LAYOUT_STEREO; ibps = avctx->bit_rate / (1000 * avctx->channels); if (ibps > 255) { av_log(avctx, AV_LOG_ERROR, "unsupported per channel bitrate %dkbps\n", ibps); return AVERROR_INVALIDDATA; } switch ((isampf << 8) + ibps) { case (8 <<8) + 8: tctx->mtab = &mode_08_08; break; case (11<<8) + 8: tctx->mtab = &mode_11_08; break; case (11<<8) + 10: tctx->mtab = &mode_11_10; break; case (16<<8) + 16: tctx->mtab = &mode_16_16; break; case (22<<8) + 20: tctx->mtab = &mode_22_20; break; case (22<<8) + 24: tctx->mtab = &mode_22_24; break; case (22<<8) + 32: tctx->mtab = &mode_22_32; break; case (44<<8) + 40: tctx->mtab = &mode_44_40; break; case (44<<8) + 48: tctx->mtab = &mode_44_48; break; default: av_log(avctx, AV_LOG_ERROR, "This version does not support %d kHz - %d kbit/s/ch mode.\n", isampf, isampf); return -1; } ff_dsputil_init(&tctx->dsp, avctx); avpriv_float_dsp_init(&tctx->fdsp, avctx->flags & CODEC_FLAG_BITEXACT); if ((ret = init_mdct_win(tctx))) { av_log(avctx, AV_LOG_ERROR, "Error initializing MDCT\n"); twin_decode_close(avctx); return ret; } init_bitstream_params(tctx); memset_float(tctx->bark_hist[0][0], 0.1, FF_ARRAY_ELEMS(tctx->bark_hist)); avcodec_get_frame_defaults(&tctx->frame); avctx->coded_frame = &tctx->frame; return 0; }