Public bug reported:

This is a kind of follow-up to a bug I posted last year, here:

https://bugs.launchpad.net/ubuntu/+source/gpac/+bug/1176596

The problem: MP4Box crashes in Raring when importing a chapters text-
file. As I noted in the above bug report, this problem effectively
prevents OGMrip from ripping a DVD to mp4-format - at least directly.

Some work seems to have been done on this bug in Trusty, because if we
now use MP4Box to import a chapters file, say like so:

azed@azed-N110:~$ MP4Box -new -nodrop -brand mp42 -itags name="KDoc"
-add KDoc.mp4#video -add KDoc.mp4#audio -chap KDoc.txt KDoc2.mp4

There's no problem:

IsoMedia import KDoc.mp4 - track ID 201 - Video (size 368 x 208)
Warning: track ID 201 has references to a track not imported
IsoMedia import KDoc.mp4 - track ID 101 - Audio (SR 48000 - 2 channels)
Warning: track ID 201 has references to a track not imported
Warning: track ID 101 has references to a track not imported
[Chapter import] Guessed video frame rate 29.97 (30000:1001)
Saving KDoc2.mp4: 0.500 secs Interleaving
azed@azed-N110:~$

So OGMrip now works OK, then?

Unfortunately not. Everything goes fine until we get to the final file-
merging stage:

Importing AAC: |==================  | (90/100)
Importing AAC: |==================  | (91/100)
Importing AAC: |==================  | (92/100)
Importing AAC: |==================  | (93/100)
Importing AAC: |==================  | (94/100)
Importing AAC: |=================== | (95/100)
Importing AAC: |=================== | (96/100)
Importing AAC: |=================== | (97/100)
Importing AAC: |=================== | (98/100)
                                                     
Converting to ISMA Audio-Video MP4 file...
[Chapter import] Guessed video frame rate 29.97 (30000:1001)

(me again) and at this point the ap dies.

What's gone wrong?

We recall that OGMrip builds its mp4 outfile out of raw video and audio
files (it actually encodes the video to avi-format with a "dummy" audio-
track, and then extracts the raw video using MP4Box with the -aviraw
option)

OK, as an experiment, let's unbundle our original mp4 into its component
raw-audio and raw-video parts (we already have the chapters file), and
see if we can put them back together again a la OGMrip. Thus, we obtain
the track IDs with:

azed@azed-N110:~$MP4Box KDoc.mp4 -info

Then extract the raw video with (in this case):

azed@azed-N110:~$MP4Box KDoc.mp4 -raw 201
Extracting MPEG-4 AVC-H264 stream to h264
azed@azed-N110:~$

[The track actually appears as: "KDoc_track201.h264"]

And the raw audio with:

azed@azed-N110:~$MP4Box -raw 101
Extracting MPEG-4 AAC
azed@azed-N110:~$

[MP4Box o/ps the track as: "KDoc-track101.aac"

We can now try to build our new mp4 with, say:

azed@azed-N110:~$ MP4Box -new -nodrop -brand mp42 -itags name="KDoc"
-add KDoc2_track201.h264:fmt=h264:fps=29.970#video -add
KDoc2_track101.aac:fmt=aac:lang=eng:group=1#audio -chap KDoc.txt
KDoc2.mp4

we get:

AVC-H264 import - frame size 368 x 208 at 29.970 FPS
AVC Import results: 5933 samples - Slices: 30 I 2883 P 3019 B - 1 SEI - 28 IDR
Stream uses forward prediction - stream CTS offset: 2 frames
AAC import  - sample rate 48000 - MPEG-4 audio - 2 channels
[Chapter import] Guessed video frame rate 29.97 (30000:1001)
Segmentation fault (core dumped)
azed@azed-N110:~$

i.e., the ap crashes.

But if we now omit the chapters-file:

azed@azed-N110:~$ MP4Box -new -nodrop -brand mp42 -itags name="KDoc" -add 
KDoc2_track201.h264:fmt=h264:fps=29.970#video -add 
KDoc2_track101.aac:fmt=aac:lang=eng:group=1#audio KDoc2.mp4
AVC-H264 import - frame size 368 x 208 at 29.970 FPS
AVC Import results: 5933 samples - Slices: 30 I 2883 P 3019 B - 1 SEI - 28 IDR
Stream uses forward prediction - stream CTS offset: 2 frames
AAC import  - sample rate 48000 - MPEG-4 audio - 2 channels
Saving KDoc2.mp4: 0.500 secs Interleaving            
azed@azed-N110:~$

Then everything is fine.

And we can even, now, add the chapters-file back in:

azed@azed-N110:~$ MP4Box -new -nodrop -brand mp42 -itags name="KDoc2" -add 
KDoc2.mp4#video -add KDoc2.mp4#audio -chap KDoc.txt KDoc2.mp4
IsoMedia import KDoc2.mp4 - track ID 1 - Video (size 368 x 208)
IsoMedia import KDoc2.mp4 - track ID 2 - Audio (SR 48000 - 2 channels)
[Chapter import] Guessed video frame rate 29.97 (30000:1001)
Saving KDoc2.mp4: 0.500 secs Interleaving
azed@azed-N110:~$

Odd.

Questions

1. Is there any chance of this annoying little bug being fixed in the
near future?

If the answer to the above is: NO

2. Would compiling and installing the latest gpac in my system help
matters?

** Affects: gpac (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: chapters mp4box ogmrip

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https://bugs.launchpad.net/bugs/1312330

Title:
  MP4Box crashes in trusty importing chapters file with raw video

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