Merge pull request #826 from wader/mpeg_es_ios_descriptors

mpeg_es: Support ES_ID_Inc and decode descriptors for IOD tags
wader · Dec 6, 2023 · 86e6d58 · 86e6d58
2 parents d284808 + fca55b2
commit 86e6d58
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Showing 4 changed files with 33 additions and 0 deletions.
diff --git a/format/mp4/testdata/iods_box_es_iod_decrs b/format/mp4/testdata/iods_box_es_iod_decrs
diff --git a/format/mp4/testdata/iods_box_es_iod_decrs.fqtest b/format/mp4/testdata/iods_box_es_iod_decrs.fqtest
@@ -0,0 +1,23 @@
+$ fq -d mp4 -o force=true d iods_box_es_iod_decrs
+    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|.{}: iods_box_es_iod_decrs (mp4)
+    |                                               |                |  boxes[0:1]:
+    |                                               |                |    [0]{}: box
+0x00|00 00 00 21                                    |...!            |      size: 33
+0x00|            69 6f 64 73                        |    iods        |      type: "iods" (Object Descriptor container box)
+0x00|                        00 00 00 00            |        ....    |      version: 0
+    |00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f|0123456789abcdef|      descriptor{}: (mpeg_es)
+0x00|                                    10         |            .   |        tag_id: "MP4_IOD_Tag" (16)
+0x00|                                       80 80 80|             ...|        length: 16
+0x10|10                                             |.               |
+0x10|   00 4f                                       | .O             |        od_id: 79
+0x10|         ff                                    |   .            |        od_profile_level: 255
+0x10|            ff                                 |    .           |        scene_profile_level: 255
+0x10|               31                              |     1          |        audio_profile_level: 49
+0x10|                  ff                           |      .         |        video_profile_level: 255
+0x10|                     ff                        |       .        |        graphics_profile_level: 255
+    |                                               |                |        descriptors[0:1]:
+    |                                               |                |          [0]{}: desc
+0x10|                        0e                     |        .       |            tag_id: "ES_ID_IncTag" (14)
+0x10|                           80 80 80 04         |         ....   |            length: 4
+0x10|                                       00 00 00|             ...|            track_id: 1
+0x20|01|                                            |.|              |
diff --git a/format/mp4/testdata/stz2.fqtest b/format/mp4/testdata/stz2.fqtest
@@ -56,6 +56,7 @@ $ fq -d mp4 'dv' stz2.mp4
 0x090|                              fe               |          .     |            audio_profile_level: 254 0x9a-0x9b (1)
 0x090|                                 ff            |           .    |            video_profile_level: 255 0x9b-0x9c (1)
 0x090|                                    ff         |            .   |            graphics_profile_level: 255 0x9c-0x9d (1)
+     |                                               |                |            descriptors[0:0]: 0x9d-0x9d (0)
      |                                               |                |        [2]{}: box 0x9d-0x27c (479)
 0x090|                                       00 00 01|             ...|          size: 479 0x9d-0xa1 (4)
 0x0a0|df                                             |.               |

diff --git a/format/mpeg/mpeg_es.go b/format/mpeg/mpeg_es.go
@@ -264,13 +264,22 @@ func odDecodeTag(d *decode.D, edc *esDecodeContext, _ int, fn func(d *decode.D))
 		// TODO: where is the spec?
 		// https://xhelmboyx.tripod.com/formats/mp4-layout.txt
 		// https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/movenc.c mov_write_iods_tag
+		// TODO: IOD = initial object descriptor?
 		MP4_IOD_Tag: func(d *decode.D) {
 			d.FieldU16("od_id")
 			d.FieldU8("od_profile_level")
 			d.FieldU8("scene_profile_level")
 			d.FieldU8("audio_profile_level")
 			d.FieldU8("video_profile_level")
 			d.FieldU8("graphics_profile_level")
+			d.FieldArray("descriptors", func(d *decode.D) {
+				for !d.End() {
+					fieldODDecodeTag(d, edc, "desc", -1, nil)
+				}
+			})
+		},
+		ES_ID_IncTag: func(d *decode.D) {
+			d.FieldU32("track_id")
 		},
 	}