static int encode_init(AVCodecContext * avctx){ WMACodecContext *s = avctx->priv_data; int i, flags1, flags2; uint8_t *extradata; s->avctx = avctx; if(avctx->channels > MAX_CHANNELS) { av_log(avctx, AV_LOG_ERROR, "too many channels: got %i, need %i or fewer", avctx->channels, MAX_CHANNELS); return AVERROR(EINVAL); } if (avctx->sample_rate > 48000) { av_log(avctx, AV_LOG_ERROR, "sample rate is too high: %d > 48kHz", avctx->sample_rate); return AVERROR(EINVAL); } if(avctx->bit_rate < 24*1000) { av_log(avctx, AV_LOG_ERROR, "bitrate too low: got %i, need 24000 or higher\n", avctx->bit_rate); return AVERROR(EINVAL); } /* extract flag infos */ flags1 = 0; flags2 = 1; if (avctx->codec->id == CODEC_ID_WMAV1) { extradata= av_malloc(4); avctx->extradata_size= 4; AV_WL16(extradata, flags1); AV_WL16(extradata+2, flags2); } else if (avctx->codec->id == CODEC_ID_WMAV2) { extradata= av_mallocz(10); avctx->extradata_size= 10; AV_WL32(extradata, flags1); AV_WL16(extradata+4, flags2); }else av_assert0(0); avctx->extradata= extradata; s->use_exp_vlc = flags2 & 0x0001; s->use_bit_reservoir = flags2 & 0x0002; s->use_variable_block_len = flags2 & 0x0004; if (avctx->channels == 2) s->ms_stereo = 1; ff_wma_init(avctx, flags2); /* init MDCT */ for(i = 0; i < s->nb_block_sizes; i++) ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0, 1.0); s->block_align = avctx->bit_rate * (int64_t)s->frame_len / (avctx->sample_rate * 8); s->block_align = FFMIN(s->block_align, MAX_CODED_SUPERFRAME_SIZE); avctx->block_align = s->block_align; avctx->bit_rate = avctx->block_align * 8LL * avctx->sample_rate / s->frame_len; //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d\n", s->block_align, avctx->bit_rate, s->frame_len, avctx->sample_rate); avctx->frame_size = avctx->delay = s->frame_len; #if FF_API_OLD_ENCODE_AUDIO avctx->coded_frame = &s->frame; avcodec_get_frame_defaults(avctx->coded_frame); #endif return 0; }