Ticket #11627: 0002-fix-also-allow-demuxing-iamf-to-iamf-mp4-without-spe.patch

libavformat/iamfdec.c

@@ -75 +75 @@
     IAMFContext *const iamf = &c->iamf;
     int ret;
 
+    int64_t old_offset = avio_tell(s->pb);
+
     ret = ff_iamfdec_read_descriptors(iamf, s->pb, INT_MAX, s);
     if (ret < 0)
         return ret;
 
+    int64_t cur_offset = avio_tell(s->pb);
+    size_t descriptors_size = cur_offset - old_offset;
+
     for (int i = 0; i < iamf->nb_audio_elements; i++) {
         IAMFAudioElement *audio_element = iamf->audio_elements[i];
         AVStreamGroup *stg = avformat_stream_group_create(s, AV_STREAM_GROUP_PARAMS_IAMF_AUDIO_ELEMENT, NULL);
@@ -113 +118 @@
                 st->disposition |= AV_DISPOSITION_DEPENDENT;
             st->id = substream->audio_substream_id;
             avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+       
+            // save a copy of the descriptors on the side data for later use when encoding raw IAMF
+            if (i == 0 && j == 0) { 
+                //we only look at the first stream later
+                if (!av_packet_side_data_new(&st->codecpar->coded_side_data,
+                    &st->codecpar->nb_coded_side_data,
+                    AV_PKT_DATA_IAMF_DESCRIPTORS,
+                    descriptors_size, 0)) {
+                    return AVERROR(ENOMEM);
+                }
+                avio_seek(s->pb, old_offset, SEEK_SET);
+                ret = avio_read(s->pb, st->codecpar->coded_side_data->data, descriptors_size);
+                if (ret != descriptors_size)
+                    return ret < 0 ? ret : AVERROR_INVALIDDATA;
+                avio_seek(s->pb, cur_offset, SEEK_SET);
+            }
         }
     }
 

libavformat/iamfenc.c

@@ -128 +128 @@
             ret = ff_iamf_fill_codec_config(iamf, stg, cc);
             if (ret < 0)
                 return ret;
+            audio_element->codec_config_id = ret;
         }
 
         return 0;