ffmpeg | branch: master | James Almer <jamr...@gmail.com> | Tue Jun 17 22:12:35 2025 -0300| [75c514e468ede184940cfa7b1c623045eed60e2e] | committer: James Almer
avformat/iamf_writer: add extra constrains for Parameter Sets in Audio Elements Signed-off-by: James Almer <jamr...@gmail.com> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=75c514e468ede184940cfa7b1c623045eed60e2e --- libavformat/iamf_writer.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-) diff --git a/libavformat/iamf_writer.c b/libavformat/iamf_writer.c index 635d1989ef..37e75dc01a 100644 --- a/libavformat/iamf_writer.c +++ b/libavformat/iamf_writer.c @@ -248,6 +248,11 @@ int ff_iamf_add_audio_element(IAMFContext *iamf, const AVStreamGroup *stg, void } else { AVBPrint bp; + if (iamf_audio_element->nb_layers < 1) { + av_log(log_ctx, AV_LOG_ERROR, "Invalid amount of layers for CHANNEL_BASED audio element. Must be >= 1\n"); + return AVERROR(EINVAL); + } + for (int j, i = 0; i < iamf_audio_element->nb_layers; i++) { const AVIAMFLayer *layer = iamf_audio_element->layers[i]; @@ -741,13 +746,40 @@ static int iamf_write_audio_element(const IAMFContext *iamf, for (int i = 0; i < audio_element->nb_substreams; i++) ffio_write_leb(dyn_bc, audio_element->substreams[i].audio_substream_id); - if (element->nb_layers == 1) + /* When audio_element_type = 1, num_parameters SHALL be set to 0 */ + if (element->audio_element_type == AV_IAMF_AUDIO_ELEMENT_TYPE_SCENE) + param_definition_types = 0; + else { + int layout = 0, expanded_layout = 0; + get_loudspeaker_layout(element->layers[0], &layout, &expanded_layout); + /* When the loudspeaker_layout = 15, the type PARAMETER_DEFINITION_DEMIXING SHALL NOT be present. */ + if (layout == 15) + param_definition_types &= ~AV_IAMF_PARAMETER_DEFINITION_DEMIXING; + /* When the loudspeaker_layout of the (non-)scalable channel audio (i.e., num_layers = 1) is less than or equal to 3.1.2ch, + * (i.e., Mono, Stereo, or 3.1.2ch), the type PARAMETER_DEFINITION_DEMIXING SHALL NOT be present. */ + else if (element->nb_layers == 1 && (layout == 0 || layout == 1 || layout == 8)) param_definition_types &= ~AV_IAMF_PARAMETER_DEFINITION_DEMIXING; + /* When num_layers > 1, the type PARAMETER_DEFINITION_RECON_GAIN SHALL be present */ if (element->nb_layers > 1) param_definition_types |= AV_IAMF_PARAMETER_DEFINITION_RECON_GAIN; + /* When codec_id = fLaC or ipcm, the type PARAMETER_DEFINITION_RECON_GAIN SHALL NOT be present. */ if (codec_config->codec_tag == MKTAG('f','L','a','C') || codec_config->codec_tag == MKTAG('i','p','c','m')) param_definition_types &= ~AV_IAMF_PARAMETER_DEFINITION_RECON_GAIN; + if ((param_definition_types & AV_IAMF_PARAMETER_DEFINITION_DEMIXING) && !element->demixing_info) { + if (element->nb_layers > 1) { + get_loudspeaker_layout(element->layers[element->nb_layers-1], &layout, &expanded_layout); + /* When the highest loudspeaker_layout of the scalable channel audio (i.e., num_layers > 1) is greater than 3.1.2ch, + * (i.e., 5.1.2ch, 5.1.4ch, 7.1.2ch, or 7.1.4ch), type PARAMETER_DEFINITION_DEMIXING SHALL be present. */ + if (layout == 3 && layout == 4 && layout == 6 && layout == 7) { + av_log(log_ctx, AV_LOG_ERROR, "demixing_info needed but not set in Stream Group #%u\n", + audio_element->audio_element_id); + return AVERROR(EINVAL); + } + } + param_definition_types &= ~AV_IAMF_PARAMETER_DEFINITION_DEMIXING; + } + } ffio_write_leb(dyn_bc, av_popcount(param_definition_types)); // num_parameters @@ -756,12 +788,6 @@ static int iamf_write_audio_element(const IAMFContext *iamf, const IAMFParamDefinition *param_def; const AVIAMFDemixingInfo *demix; - if (!param) { - av_log(log_ctx, AV_LOG_ERROR, "demixing_info needed but not set in Stream Group #%u\n", - audio_element->audio_element_id); - return AVERROR(EINVAL); - } - demix = av_iamf_param_definition_get_subblock(param, 0); ffio_write_leb(dyn_bc, AV_IAMF_PARAMETER_DEFINITION_DEMIXING); // type _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
