[BUG] Hybrid fails to extract tx3g subtitles from a mp4 container

[Dan64]

I have a mp4 file with 3 subtitles. I attached to this post the file HybridDebugOutput.txt and the ouput of mediainfo.

Looking at the debug output it is possible to see at row 3235 that the first subtitle is recognized as "tx3g" and is extracted correctly. But at row 3552 it is possible to see that Hybrid fails to extract the second subtitle, I also have some doubt that the subtitle has been recognized as "tx3g" so is not clear to me what command is using Hybrid to extract the second subtitle.

[Selur]

Hybrid uses:

"D:/Programs/Hybrid\64bit\MP4Box.exe" "E:\TVshows\X-Files\X-Files 08x01.mp4" -srt 4 -out "E:\TVshows\X-Files\X-Files 08x01_lang_it.srt"

which should extract the subtitle track with id 4 as srt file. Which should be correct according to https://github.com/gpac/gpac/wiki/Subtitling-with-GPAC (4.)

Do you get an error when calling that call in a Windows Command Prompt?

What confuses me is that you wrote that the extraction of the second subtitle stream fails, but according to the log the extraction of the first stream fails.

found Subtitles: 0,it,4,3,tx3g,,Timed Text ### 1,it,5,4,tx3g,,Timed Text ### 2,en,6,5,tx3g,,Timed Text

and the error states:

2020.12.28 - 19:15:38_Windows 10 Version 1909 (64bit)_2020.12.13.1 - level 9: extractorFinished 'mp4box_subtitleExtractor' for: E:\TVshows\X-Files\X-Files 08x01_lang_it_4_text.srt 2020.12.28 - 19:15:38_Windows 10 Version 1909 (64bit)_2020.12.13.1 - level 9: Couldn't extract: E:\TVshows\X-Files\X-Files 08x01_lang_it_4_text.srt

also I see no indication that the 1st stream was extracted in the debug output.
Just checked the code Hybrid checked whether the expected output file (E:\TVshows\X-Files\X-Files 08x01_lang_it_4_text.srt) exists after MP4Box finished.
If the file really exists, my guess would be that some virus scanner or similar is blocking the access to it for a short time (a few ms) after creation, which is why Hybrid can't access it and thus assumes it doesn't exist.
So if you are running a virus scanner or similar software make sure it does not scan the temp folder while Hybrid is working.

Cu Selur

[Dan64]

I disabled the Microsoft antivirus, but the problem is still showing. The first subtitle get extracted even if the dialog error box shows that Hybrid failed to extract the subtitle. The Hybrid GUI remain "frozen" and I have to kill the application, in this situation all the remaining subtitles are not extracted.

Then I tried to perform the following test:

1) I used "My MP4Box GUI" to extract the subtitles (see attached image)

2) I used MKVtoolnix GUI to convert the mp4 container in mkv. For some reason also this tool is unable to get the subtitles (but this is an old problem), so I had to add the subtitles extracted previously with "My MP4Box GUI"

3) I used Hybrid to encode the movie and in this case the subtitles get extracted correctly and the encoding completed successfully.

So it seems that the problem is related only to mp4 containers.

[Selur]

So it seems that the problem is related only to mp4 containers.

no surprise there,..

Can't reproduce the issue with test files I have.

So the question remains:

Do you get an error when calling that call in a Windows Command Prompt?

If you have a small sample which allows me to reproduce the issue I can look into it.

Cu Selur

[Dan64]

It is better that you try to reproduce the problem.

You can find a sample of movie at the following link (*)

https://file.re/2020/12/28/x-files-08x01001/

Thanks

(*) The link will expiry at December 29, 2020, at 09:49 PM (CET) - Local time: 21:59 PM (CET)

[Selur]

Got the file.
Will look at it tomorrow. (on my way to bed now)

Cu Selur

[Selur]

I can reproduce the issue.
Will look into it.
One problem: looking at the file in a MPC-HC I see no subtitles for the first subtitle track.
Analyzing the file with MP4Box:

* Movie Info * Timescale 600 - 7 tracks Computed Duration 00:06:10.411 - Indicated Duration 00:06:10.411 Fragmented File: no File suitable for progressive download (moov before mdat) File Brand isom - version 1 Compatible brands: isom Created: GMT Mon Dec 28 20:41:56 2020 Modified: GMT Mon Dec 28 20:41:56 2020 File has root IOD (9 bytes) Scene PL 0xff - Graphics PL 0xff - OD PL 0xff Visual PL: Not part of MPEG-4 Visual profiles (0xfe) Audio PL: Not part of MPEG-4 audio profiles (0xfe) No streams included in root OD Track # 1 Info - TrackID 1 - TimeScale 90000 Media Duration 00:06:10.369 - Indicated Duration 00:06:10.369 Media Info: Language "Undetermined (und)" - Type "vide:avc1" - 8880 samples Visual Sample Entry Info: width=1918 height=1080 (depth=24 bits) Visual Track layout: x=0 y=0 width=1918 height=1080 MPEG-4 Config: Visual Stream - ObjectTypeIndication 0x21 AVC/H264 Video - Visual Size 1918 x 1080 AVC Info: 1 SPS - 1 PPS - Profile High @ Level 4.1 NAL Unit length bits: 32 Pixel Aspect Ratio 1:1 - Indicated track size 1918 x 1080 Chroma format YUV 4:2:0 - Luma bit depth 8 - chroma bit depth 8 SPS#1 hash: E4541CFCC32BF4EB9EB9A3D26E642B5B4A3B822C PPS#1 hash: DB21ED7C621CDEF25CC891200B5A104273B15E6A Self-synchronized RFC6381 Codec Parameters: avc1.640029 Average GOP length: 83 samples Max sample duration: 3754 / 90000 Track # 2 Info - TrackID 2 - TimeScale 48000 Media Duration 00:06:10.410 - Indicated Duration 00:06:10.410 Media Info: Language "Italian (ita)" - Type "soun:mp4a" - 17363 samples 1 UDTA types: name (1) MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x40 MPEG-4 Audio AAC LC (AOT=2 implicit) - 2 Channel(s) - SampleRate 48000 Synchronized on stream 1 RFC6381 Codec Parameters: mp4a.40.2 Alternate Group ID 1 All samples are sync Max sample duration: 1024 / 48000 Track # 3 Info - TrackID 3 - TimeScale 48000 Media Duration 00:06:10.410 - Indicated Duration 00:06:10.410 Track is disabled Media Info: Language "English (eng)" - Type "soun:mp4a" - 17363 samples 1 UDTA types: name (1) Surround MPEG-4 Config: Audio Stream - ObjectTypeIndication 0x40 MPEG-4 Audio AAC LC (AOT=2 implicit) - 6 Channel(s) - SampleRate 48000 Synchronized on stream 1 RFC6381 Codec Parameters: mp4a.40.2 Alternate Group ID 1 All samples are sync Max sample duration: 1024 / 48000 Track # 4 Info - TrackID 4 - TimeScale 90000 Media Duration 00:06:10.411 - Indicated Duration 00:06:10.411 Media Info: Language "Italian (ita)" - Type "sbtl:tx3g" - 1 samples Unknown Text Stream Size 1918 x 60 - Translation X=0 Y=0 - Layer 0 RFC6381 Codec Parameters: tx3g Alternate Group ID 3 All samples are sync Max sample duration: 33337053 / 90000 Track # 5 Info - TrackID 5 - TimeScale 90000 Media Duration 00:06:08.259 - Indicated Duration 00:06:08.259 Track is disabled Media Info: Language "Italian (ita)" - Type "sbtl:tx3g" - 57 samples Unknown Text Stream Size 1918 x 60 - Translation X=0 Y=0 - Layer 0 RFC6381 Codec Parameters: tx3g Alternate Group ID 3 All samples are sync Max sample duration: 20789730 / 90000 Track # 6 Info - TrackID 6 - TimeScale 90000 Media Duration 00:06:08.335 - Indicated Duration 00:06:08.335 Track is disabled Media Info: Language "English (eng)" - Type "sbtl:tx3g" - 61 samples Unknown Text Stream Size 1918 x 60 - Translation X=0 Y=0 - Layer 0 RFC6381 Codec Parameters: tx3g Alternate Group ID 3 All samples are sync Max sample duration: 20789730 / 90000 Track # 7 Info - TrackID 7 - TimeScale 1000 Media Duration 00:05:09.351 - Indicated Duration 00:05:09.351 Track is disabled Media Info: Language "Undetermined (und)" - Type "text:text" - 3 samples Unknown Text Stream Size 0 x 0 - Translation X=0 Y=0 - Layer 0 RFC6381 Codec Parameters: text All samples are sync Max sample duration: 205497 / 1000

Calling:

MP4Box.exe c:\Users\Selur\Desktop\x-files-08x01001.mp4 -srt 4 -out "e:\Output\test.srt"

Produces an empty output. (extracting the other streams works fine)
-> I'll look into Hybrid not freezing on extraction, but if the output is empty Hybrid will complain.

Cu Selur

[Selur]

Found the cause of the problem.
Hybrid calls MP4Box with "X-Files 08x01_lang_it.srt" but expects the output to be names "X-Files 08x01_lang_it_4_text.srt"
-> fixing it

[Selur]

Send you a link to a dev version via PM which should fix the issue.
-> please test and report back, thx.

Cu Selur

[Dan64]

Sent you PM with my feedback.