Function write_parameter_block

libavformat/iamf_writer.c:1012–1135

}

static int write_parameter_block(const IAMFContext *iamf, AVIOContext *pb,
                                 const AVIAMFParamDefinition *param, void *log_ctx)
{
    uint8_t header[MAX_IAMF_OBU_HEADER_SIZE];
    const IAMFParamDefinition *param_definition = ff_iamf_get_param_definition(iamf, param->parameter_id);
    PutBitContext pbc;
    AVIOContext *dyn_bc;
    uint8_t *dyn_buf = NULL;
    int dyn_size, ret;

    if (param->type > AV_IAMF_PARAMETER_DEFINITION_RECON_GAIN) {
        av_log(log_ctx, AV_LOG_DEBUG, "Ignoring side data with unknown type %u\n",
               param->type);
        return 0;
    }

    if (!param_definition) {
        av_log(log_ctx, AV_LOG_ERROR, "Non-existent Parameter Definition with ID %u referenced by a packet\n",
               param->parameter_id);
        return AVERROR(EINVAL);
    }

    if (param->type != param_definition->param->type) {
        av_log(log_ctx, AV_LOG_ERROR, "Inconsistent values for Parameter Definition "
                                "with ID %u in a packet\n",
               param->parameter_id);
        return AVERROR(EINVAL);
    }

    ret = avio_open_dyn_buf(&dyn_bc);
    if (ret < 0)
        return ret;

    // Sequence Header
    init_put_bits(&pbc, header, sizeof(header));
    put_bits(&pbc, 5, IAMF_OBU_IA_PARAMETER_BLOCK);
    put_bits(&pbc, 3, 0);
    flush_put_bits(&pbc);
    avio_write(pb, header, put_bytes_count(&pbc, 1));

    ffio_write_leb(dyn_bc, param->parameter_id);
    if (!param_definition->mode) {
        ffio_write_leb(dyn_bc, param->duration);
        ffio_write_leb(dyn_bc, param->constant_subblock_duration);
        if (param->constant_subblock_duration == 0)
            ffio_write_leb(dyn_bc, param->nb_subblocks);
    }

    for (int i = 0; i < param->nb_subblocks; i++) {
        const void *subblock = av_iamf_param_definition_get_subblock(param, i);

        switch (param->type) {
        case AV_IAMF_PARAMETER_DEFINITION_MIX_GAIN: {
            const AVIAMFMixGain *mix = subblock;
            if (!param_definition->mode && param->constant_subblock_duration == 0)
                ffio_write_leb(dyn_bc, mix->subblock_duration);

            ffio_write_leb(dyn_bc, mix->animation_type);