int avresample_open(AVAudioResampleContext *avr) { int ret; /* set channel mixing parameters */ avr->in_channels = av_get_channel_layout_nb_channels(avr->in_channel_layout); if (avr->in_channels <= 0 || avr->in_channels > AVRESAMPLE_MAX_CHANNELS) { av_log(avr, AV_LOG_ERROR, "Invalid input channel layout: %"PRIu64"\n", avr->in_channel_layout); return AVERROR(EINVAL); } avr->out_channels = av_get_channel_layout_nb_channels(avr->out_channel_layout); if (avr->out_channels <= 0 || avr->out_channels > AVRESAMPLE_MAX_CHANNELS) { av_log(avr, AV_LOG_ERROR, "Invalid output channel layout: %"PRIu64"\n", avr->out_channel_layout); return AVERROR(EINVAL); } avr->resample_channels = FFMIN(avr->in_channels, avr->out_channels); avr->downmix_needed = avr->in_channels > avr->out_channels; avr->upmix_needed = avr->out_channels > avr->in_channels || avr->am->matrix || (avr->out_channels == avr->in_channels && avr->in_channel_layout != avr->out_channel_layout); avr->mixing_needed = avr->downmix_needed || avr->upmix_needed; /* set resampling parameters */ avr->resample_needed = avr->in_sample_rate != avr->out_sample_rate || avr->force_resampling; /* select internal sample format if not specified by the user */ if (avr->internal_sample_fmt == AV_SAMPLE_FMT_NONE && (avr->mixing_needed || avr->resample_needed)) { enum AVSampleFormat in_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt); enum AVSampleFormat out_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt); int max_bps = FFMAX(av_get_bytes_per_sample(in_fmt), av_get_bytes_per_sample(out_fmt)); if (max_bps <= 2) { avr->internal_sample_fmt = AV_SAMPLE_FMT_S16P; } else if (avr->mixing_needed) { avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP; } else { if (max_bps <= 4) { if (in_fmt == AV_SAMPLE_FMT_S32P || out_fmt == AV_SAMPLE_FMT_S32P) { if (in_fmt == AV_SAMPLE_FMT_FLTP || out_fmt == AV_SAMPLE_FMT_FLTP) { /* if one is s32 and the other is flt, use dbl */ avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP; } else { /* if one is s32 and the other is s32, s16, or u8, use s32 */ avr->internal_sample_fmt = AV_SAMPLE_FMT_S32P; } } else { /* if one is flt and the other is flt, s16 or u8, use flt */ avr->internal_sample_fmt = AV_SAMPLE_FMT_FLTP; } } else { /* if either is dbl, use dbl */ avr->internal_sample_fmt = AV_SAMPLE_FMT_DBLP; } } av_log(avr, AV_LOG_DEBUG, "Using %s as internal sample format\n", av_get_sample_fmt_name(avr->internal_sample_fmt)); } /* set sample format conversion parameters */ if (avr->in_channels == 1) avr->in_sample_fmt = av_get_planar_sample_fmt(avr->in_sample_fmt); if (avr->out_channels == 1) avr->out_sample_fmt = av_get_planar_sample_fmt(avr->out_sample_fmt); avr->in_convert_needed = (avr->resample_needed || avr->mixing_needed) && avr->in_sample_fmt != avr->internal_sample_fmt; if (avr->resample_needed || avr->mixing_needed) avr->out_convert_needed = avr->internal_sample_fmt != avr->out_sample_fmt; else avr->out_convert_needed = avr->in_sample_fmt != avr->out_sample_fmt; /* allocate buffers */ if (avr->mixing_needed || avr->in_convert_needed) { avr->in_buffer = ff_audio_data_alloc(FFMAX(avr->in_channels, avr->out_channels), 0, avr->internal_sample_fmt, "in_buffer"); if (!avr->in_buffer) { ret = AVERROR(EINVAL); goto error; } } if (avr->resample_needed) { avr->resample_out_buffer = ff_audio_data_alloc(avr->out_channels, 0, avr->internal_sample_fmt, "resample_out_buffer"); if (!avr->resample_out_buffer) { ret = AVERROR(EINVAL); goto error; } } if (avr->out_convert_needed) { avr->out_buffer = ff_audio_data_alloc(avr->out_channels, 0, avr->out_sample_fmt, "out_buffer"); if (!avr->out_buffer) { ret = AVERROR(EINVAL); goto error; } } avr->out_fifo = av_audio_fifo_alloc(avr->out_sample_fmt, avr->out_channels, 1024); if (!avr->out_fifo) { ret = AVERROR(ENOMEM); goto error; } /* setup contexts */ if (avr->in_convert_needed) { avr->ac_in = ff_audio_convert_alloc(avr, avr->internal_sample_fmt, avr->in_sample_fmt, avr->in_channels); if (!avr->ac_in) { ret = AVERROR(ENOMEM); goto error; } } if (avr->out_convert_needed) { enum AVSampleFormat src_fmt; if (avr->in_convert_needed) src_fmt = avr->internal_sample_fmt; else src_fmt = avr->in_sample_fmt; avr->ac_out = ff_audio_convert_alloc(avr, avr->out_sample_fmt, src_fmt, avr->out_channels); if (!avr->ac_out) { ret = AVERROR(ENOMEM); goto error; } } if (avr->resample_needed) { avr->resample = ff_audio_resample_init(avr); if (!avr->resample) { ret = AVERROR(ENOMEM); goto error; } } if (avr->mixing_needed) { ret = ff_audio_mix_init(avr); if (ret < 0) goto error; } return 0; error: avresample_close(avr); return ret; }