static av_cold int aac_decode_init(AVCodecContext *avctx) { AACContext *ac = avctx->priv_data; float output_scale_factor; ac->avctx = avctx; ac->oc[1].m4ac.sample_rate = avctx->sample_rate; if (avctx->extradata_size > 0) { if (decode_audio_specific_config(ac, ac->avctx, &ac->oc[1].m4ac, avctx->extradata, avctx->extradata_size*8, 1) < 0) return -1; } else { int sr, i; uint8_t layout_map[MAX_ELEM_ID*4][3]; int layout_map_tags; sr = sample_rate_idx(avctx->sample_rate); ac->oc[1].m4ac.sampling_index = sr; ac->oc[1].m4ac.channels = avctx->channels; ac->oc[1].m4ac.sbr = -1; ac->oc[1].m4ac.ps = -1; for (i = 0; i < FF_ARRAY_ELEMS(ff_mpeg4audio_channels); i++) if (ff_mpeg4audio_channels[i] == avctx->channels) break; if (i == FF_ARRAY_ELEMS(ff_mpeg4audio_channels)) { i = 0; } ac->oc[1].m4ac.chan_config = i; if (ac->oc[1].m4ac.chan_config) { int ret = set_default_channel_config(avctx, layout_map, &layout_map_tags, ac->oc[1].m4ac.chan_config); if (!ret) output_configure(ac, layout_map, layout_map_tags, ac->oc[1].m4ac.chan_config, OC_GLOBAL_HDR); else if (avctx->err_recognition & AV_EF_EXPLODE) return AVERROR_INVALIDDATA; } } if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) { avctx->sample_fmt = AV_SAMPLE_FMT_FLT; output_scale_factor = 1.0 / 32768.0; } else { avctx->sample_fmt = AV_SAMPLE_FMT_S16; output_scale_factor = 1.0; } AAC_INIT_VLC_STATIC( 0, 304); AAC_INIT_VLC_STATIC( 1, 270); AAC_INIT_VLC_STATIC( 2, 550); AAC_INIT_VLC_STATIC( 3, 300); AAC_INIT_VLC_STATIC( 4, 328); AAC_INIT_VLC_STATIC( 5, 294); AAC_INIT_VLC_STATIC( 6, 306); AAC_INIT_VLC_STATIC( 7, 268); AAC_INIT_VLC_STATIC( 8, 510); AAC_INIT_VLC_STATIC( 9, 366); AAC_INIT_VLC_STATIC(10, 462); ff_aac_sbr_init(); ff_dsputil_init(&ac->dsp, avctx); ff_fmt_convert_init(&ac->fmt_conv, avctx); avpriv_float_dsp_init(&ac->fdsp, avctx->flags & CODEC_FLAG_BITEXACT); ac->random_state = 0x1f2e3d4c; ff_aac_tableinit(); INIT_VLC_STATIC(&vlc_scalefactors,7,FF_ARRAY_ELEMS(ff_aac_scalefactor_code), ff_aac_scalefactor_bits, sizeof(ff_aac_scalefactor_bits[0]), sizeof(ff_aac_scalefactor_bits[0]), ff_aac_scalefactor_code, sizeof(ff_aac_scalefactor_code[0]), sizeof(ff_aac_scalefactor_code[0]), 352); ff_mdct_init(&ac->mdct, 11, 1, output_scale_factor/1024.0); ff_mdct_init(&ac->mdct_small, 8, 1, output_scale_factor/128.0); ff_mdct_init(&ac->mdct_ltp, 11, 0, -2.0/output_scale_factor); // window initialization ff_kbd_window_init(ff_aac_kbd_long_1024, 4.0, 1024); ff_kbd_window_init(ff_aac_kbd_short_128, 6.0, 128); ff_init_ff_sine_windows(10); ff_init_ff_sine_windows( 7); cbrt_tableinit(); avcodec_get_frame_defaults(&ac->frame); avctx->coded_frame = &ac->frame; return 0; }