Function ffat_init_encoder

libavcodec/audiotoolboxenc.c:251–472

}

static av_cold int ffat_init_encoder(AVCodecContext *avctx)
{
    ATDecodeContext *at = avctx->priv_data;
    OSStatus status;
    int ret;

    AudioStreamBasicDescription in_format = {
        .mSampleRate = avctx->sample_rate,
        .mFormatID = kAudioFormatLinearPCM,
        .mFormatFlags = ((avctx->sample_fmt == AV_SAMPLE_FMT_FLT ||
                          avctx->sample_fmt == AV_SAMPLE_FMT_DBL) ? kAudioFormatFlagIsFloat
                        : avctx->sample_fmt == AV_SAMPLE_FMT_U8 ? 0
                        : kAudioFormatFlagIsSignedInteger)
                        | kAudioFormatFlagIsPacked,
        .mBytesPerPacket = av_get_bytes_per_sample(avctx->sample_fmt) * avctx->ch_layout.nb_channels,
        .mFramesPerPacket = 1,
        .mBytesPerFrame = av_get_bytes_per_sample(avctx->sample_fmt) * avctx->ch_layout.nb_channels,
        .mChannelsPerFrame = avctx->ch_layout.nb_channels,
        .mBitsPerChannel = av_get_bytes_per_sample(avctx->sample_fmt) * 8,
    };
    AudioStreamBasicDescription out_format = {
        .mSampleRate = avctx->sample_rate,
        .mFormatID = ffat_get_format_id(avctx->codec_id, avctx->profile),
        .mChannelsPerFrame = in_format.mChannelsPerFrame,
    };
    UInt32 layout_size = sizeof(AudioChannelLayout) +
                         sizeof(AudioChannelDescription) * avctx->ch_layout.nb_channels;
    AudioChannelLayout *channel_layout = av_malloc(layout_size);

    if (!channel_layout)
        return AVERROR(ENOMEM);

    if (avctx->codec_id == AV_CODEC_ID_ILBC) {
        int mode = get_ilbc_mode(avctx);
        out_format.mFramesPerPacket  = 8000 * mode / 1000;
        out_format.mBytesPerPacket   = (mode == 20 ? 38 : 50);
    }

    status = AudioConverterNew(&in_format, &out_format, &at->converter);

    if (status != 0) {
        av_log(avctx, AV_LOG_ERROR, "AudioToolbox init error: %i\n", (int)status);
        av_free(channel_layout);
        return AVERROR_UNKNOWN;
    }

    if (avctx->ch_layout.order == AV_CHANNEL_ORDER_UNSPEC)
        av_channel_layout_default(&avctx->ch_layout, avctx->ch_layout.nb_channels);

    if ((status = remap_layout(channel_layout, &avctx->ch_layout)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "Invalid channel layout\n");
        av_free(channel_layout);
        return status;
    }

    if (AudioConverterSetProperty(at->converter, kAudioConverterInputChannelLayout,
                                  layout_size, channel_layout)) {
        av_log(avctx, AV_LOG_ERROR, "Unsupported input channel layout\n");