[HELP] Trouble reading Pointer file in MXF type file

[3pointedit]

Problem seems to be that the mov contains pointers like:
default:VibrintAVFiles2 News Ingest:camb_730_Mackay2_2002(1).vmf:video.vid
which seems like ffmpeg can't handle.
For each stream one gets, something like:

[mov,mp4,m4a,3gp,3g2,mj2 @ 00000241a587c040] Opening 'video.vid' for reading
[mov,mp4,m4a,3gp,3g2,mj2 @ 00000241a587c040] stream 0, error opening alias: path='/VibrintAVFiles/P2 News Ingest/camb_730_Mackay2_2002(1).vmf/video.vid',
dir='camb_730_Mackay2_2002(1).vmf', filename='video.vid', volume='default', nlvl_from=1, nlvl_to=1

so the question is whether there are some additional options in your Grass Valley tool to create these files?

Cu Selur

No they are specific references to the original path. We had to copy them out to a Final Cut Pro edit suite and use them as local media. The MXF plugin for FCP loaded the clip and ignored the original path data.
Its odd too, because when I used ffmpeg earlier I was able to parse the .mov ok. This embedded path wasn't an issue and the files certainly were not in that location when I transcoded them.
The alias file it's looking for is that pointer file... does _drefs cause ffmpeg to ignore this data?

[Selur]

See: https://www.ffmpeg.org/ffmpeg-all.html#t...fQuickTime
enable_drefs: enables that external tracks can be loaded
and
use_absolute_path
Allows loading of external tracks via absolute paths, disabled by default. Enabling this poses a security risk. It should only be enabled if the source is known to be non malicious.

Problem is:
a. the absolute paths are wrong
and
b. there doesn't seem to be a way to create relative ones.

Cu Selur

[3pointedit]

See: https://www.ffmpeg.org/ffmpeg-all.html#t...fQuickTime
enable_drefs: enables that external tracks can be loaded
and
use_absolute_path
Allows loading of external tracks via absolute paths, disabled by default. Enabling this poses a security risk. It should only be enabled if the source is known to be non malicious.

Problem is:
a. the absolute paths are wrong
and
b. there doesn't seem to be a way to create relative ones.

Cu Selur

I wonder why I can get MpegStreamclip to open the file then? It deinterlaceds and down mixes the audio but it does open the files remotely for me.

[Selur]

No clue what MpegStreamclip does, but from the looks of it ffmpeg doesn't do it.

[3pointedit]

No clue what MpegStreamclip does, but from the looks of it ffmpeg doesn't do it.

When I got it to work, was it because I was using:

-use_absolute_path 1

Can that function be a user selectable switch instead of a automatic function?
Also I really appreciate you taking the time to help me, I realise that there is very little reward for your app development wise.

Just wondering if you are placing ffmpeg into the folder in the media path or trying it from outside the folder?

[Selur]

Not moving ffmpeg, but I think I got it working at least it's not crashing,... question is:
Should there some noticeable sound in the sample you shared with me? (getting 4 silent tracks atm.)

[Selur]

Small update: Got video (and I think also audio - assuming the sample you gave me contains 4 silent streams) encoding working now as long as I use FFmpeg.
Looking into mencoder/mplayer and then Avisynth and Vapoursynth.

Copying the ffmpeg binary into the folder with the mov file is not necessary as long as the working directory of ffmpeg in which ffmpeg is called is changed to that folder.
Background: ffmpeg opens the mov can't find the absolute paths, but a fallback inside the ffmpeg code causes it to also search for the files inside it's own working directory.

Cu Selur

Ps.: Copied a fast encode of the content into my GoogleDrive. (x264 crf18 ultrafast interfaced encoding)

[3pointedit]

Small update: Got video (and I think also audio - assuming the sample you gave me contains 4 silent streams) encoding working now as long as I use FFmpeg.
************

Ps.: Copied a fast encode of the content into my GoogleDrive. (x264 crf18 ultrafast interfaced encoding)

Just downloading now, thank you. Hmm, I was sure that there was audio on those streams. At least on channel 4.

---

Thats weird. VLC plays it mute but with video. FCPX plays black for video but shows a waveform on all four tracks of audio. What codec did you use for the audio streams?

Just reading that PCM audio (which is the 4 streams) is raw format audio and that vlc for example doesn't recognise the formatting. Is that the problem with ffmpeg? I really expected there to be some wind or talking as it is camera native footage. Unfortunately I cannot download my own file to check in FCPX as I don't have the bandwidth at home. Other similar files I have play the audio fine in FCPX.

[Selur]

Used aac as audio and don't get sound here too, which is why I asked whether the audio was silent or not.
-> Since it sounds like there should be sound I'll look into it some more before I look more into opening such content with Avisynth, Vapoursynth and MPlayer.

Call I use atm. and that returns a silent output is:

ffmpeg -y -enable_drefs 1 -use_absolute_path 1 -i "C:\Users\Selur\Desktop\camb_730_Mackay2_2002(1).vmf\camb_730_Mackay2_2002(1).mov" -map 0:1 -vn -sn -ac 4 -ar 48000 -filter_complex "[0:1][0:2][0:3][0:4] amerge=inputs=4" -channel_layout 4.0 -acodec pcm_s16le -f wav "H:\Output\iId_1_aid_0_lang_en_07_34_19_871000.wav"

For testing I open a command prompt in Windows, navigate to the folder where the input lies and then call ffmpeg:

g:\Hybrid\ffmpeg.exe -y -enable_drefs 1 -use_absolute_path 1 -i "C:\Users\Selur\Desktop\camb_730_Mackay2_2002(1).vmf\camb_730_Mackay2_2002(1).mov" -map 0:1 -vn -sn -ac 4 -ar 48000 -filter_complex "[0:1][0:2][0:3][0:4] amerge=inputs=4" -channel_layout 4.0 -acodec pcm_s16le -f wav "H:\Output\test.wav"

This way the working directory is the current folder and ffmpeg finds the files. No clue why the output is silent so far.

Just reading that PCM audio (which is the 4 streams) is raw format audio and that vlc for example doesn't recognise the formatting.

Real raw PCM does not come with headers so that is probably not a mistake in itself.

Unfortunately I cannot download my own file to check in FCPX as I don't have the bandwidth at home. Other similar files I have play the audio fine in FCPX.

Please report back once you could check the source you gave me in FCPX to be sure there really is audio to find.

Cu Selur

[3pointedit]

Please report back once you could check the source you gave me in FCPX to be sure there really is audio to find.

Cu Selur

Ok download completed (via phone). I can confirm that FCP finds only noise (effectively nothing) on the four audio channels.
I am going to upload another clip to G Drive but its a bit bigger sorry (3.8Gb). BUT I can guarantee that it has audio on atlas 3 of the 4 tracks.
Download from: (link to come)

P.S. if its to large I'll have to wait until next week to find a better candidate.