Technical question,plz help

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11.04.2009, 18:43

Technical question,plz help

@ soul_killer

there are numerous, read all of this topic

a better way is to watch them with VLC

or if you still want to convert

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17.01.2014, 21:52

Re: Technical question,plz help

Shirtfull wrote:if FFprobe cannot detect data in corrupt region, then the corruption is beyond repair as you probably have lost packets.
I see Confused
Excuse my ignorance when it comes to "packets" but I don't suppose there's any way to skip over the ones that are lost/corrupt?

17.01.2014, 16:15

Re: Technical question,plz help

oklahoma001 wrote:Right, if I follow correctly the keyframe is supposed to lead me to the appropriate time to cut. And in order to cut I'll be using -ss written in hours:minutes:seconds? In the text file though, there aren't any keyframes that show up within the corrupt area, the area between 3minutes25seconds and 1hour27minutes. Are you saying to cut at the 1hour27min keyframe? Because its the video in between that I'm trying to recover.

Sorry I missed The text file by the way jumps from 3m25s to 1h27m as well. in your previous post, if FFprobe cannot detect data in corrupt region, then the corruption is beyond repair as you probably have lost packets.

17.01.2014, 07:52

Re: Technical question,plz help

Shirtfull wrote:Cut at next key frame after problem, not before. you just copy error using -ss 0:03:00.294

Right, if I follow correctly the keyframe is supposed to lead me to the appropriate time to cut. And in order to cut I'll be using -ss written in hours:minutes:seconds? In the text file though, there aren't any keyframes that show up within the corrupt area, the area between 3minutes25seconds and 1hour27minutes. Are you saying to cut at the 1hour27min keyframe? Because its the video in between that I'm trying to recover.

16.01.2014, 23:47

Re: Technical question,plz help

oklahoma001 wrote:
Shirtfull wrote:---

Then search output txt file for pict_type=I (key frames)

Take time from location you've decided on and use -ss switch in FFmpeg to cut.

Okay so I went through the text file (220mb!) and chose a keyframe at 3minutes in. The corrupt mark occurs at 3m25s. I entered this into ffmpeg (hopefully this is what you meant. and the file was the same with or without the milliseconds) like so ffmpeg -i "e\input.flv" -ss 0:03:00.294 "e:\output.mkv". The video plays fine for 25 seconds then jumps to the 1hour27minute as usual. The text file by the way jumps from 3m25s to 1h27m as well.

Also, when simply putting the file into mkv via ffmpeg I get these errors at the 3m25s mark

AVC: nal size -1407318310
[h264 @ 000000000434fe40] cabac decode of qscale diff failed at 32 21
[h264 @ 000000000434fe40] error while decoding MB 32 21, bytestream (1)
[h264 @ 000000000434fe40] AVC: nal size -1407318310
[h264 @ 000000000434fe40] concealing 193 DC, 193 AC, 193 MV errors in P frame

Cut at next key frame after problem, not before. you just copy error using -ss 0:03:00.294

16.01.2014, 23:23

Re: Technical question,plz help

Shirtfull wrote:---

Then search output txt file for pict_type=I (key frames)

Take time from location you've decided on and use -ss switch in FFmpeg to cut.

Okay so I went through the text file (220mb!) and chose a keyframe at 3minutes in. The corrupt mark occurs at 3m25s. I entered this into ffmpeg (hopefully this is what you meant. and the file was the same with or without the milliseconds) like so ffmpeg -i "e\input.flv" -ss 0:03:00.294 "e:\output.mkv". The video plays fine for 25 seconds then jumps to the 1hour27minute as usual. The text file by the way jumps from 3m25s to 1h27m as well.

Also, when simply putting the file into mkv via ffmpeg I get these errors at the 3m25s mark

AVC: nal size -1407318310
[h264 @ 000000000434fe40] cabac decode of qscale diff failed at 32 21
[h264 @ 000000000434fe40] error while decoding MB 32 21, bytestream (1)
[h264 @ 000000000434fe40] AVC: nal size -1407318310
[h264 @ 000000000434fe40] concealing 193 DC, 193 AC, 193 MV errors in P frame

16.01.2014, 22:05

Re: Technical question,plz help

oklahoma001 wrote:<snip>

I've never used FFprobe til now, so the only command I could figure out was -show_streams, which indeed listed the correct duration for each file. Other commands like "-read_intervals" sound useful but i'll be damned if I could figure it out. But, given ffprobe did read the the duration properly, how would I use that information when editing the file? I still have to run the file through ffmpeg right?

Modify this to source and output file.

ffprobe -show_frames -count_frames -pretty -i "Path to file\filename" >"Path for output file\filename_tc.txt"

Then search output txt file for pict_type=I (key frames)

Take time from location you've decided on and use -ss switch in FFmpeg to cut.

16.01.2014, 20:34

Re: Technical question,plz help

Shirtfull wrote:Does timecode in text file go beyond 59min?
Assuming those numbers in the text are milliseconds no it doesn't. It ends at 3545100 (59 minutes).

Shirtfull wrote:Try FFprobe to localize error and use info gained to cut after problem area to a new file.
I've never used FFprobe til now, so the only command I could figure out was -show_streams, which indeed listed the correct duration for each file. Other commands like "-read_intervals" sound useful but i'll be damned if I could figure it out. But, given ffprobe did read the the duration properly, how would I use that information when editing the file? I still have to run the file through ffmpeg right?

16.01.2014, 11:01

Re: Technical question,plz help

oklahoma001 wrote:Working with the 2.5 hour file mentioned below (59min corrupt mark) I separated the streams with FLVextract and used yamb to join them, saving the output file as flv. I didn't spot any errors in the text, but the resultant file is only 59mins long. Basically, its the same thing I got with mkvmerge
.

Does timecode in text file go beyond 59min?

oklahoma001 wrote:However, when trying the same thing with two other files (both several hours long, both with corrupt marks within the first 10minutes) FLVextract doesn't do anything except display a message under Warning/Error that reads, "Non-negative number required.Parameter name: count"

Try FFprobe to localize error and use info gained to cut after problem area to a new file.

15.01.2014, 23:06

Re: Technical question,plz help

Working with the 2.5 hour file mentioned below (59min corrupt mark) I separated the streams with FLVextract and used yamb to join them, saving the output file as flv. I didn't spot any errors in the text, but the resultant file is only 59mins long. Basically, its the same thing I got with mkvmerge.

However, when trying the same thing with two other files (both several hours long, both with corrupt marks within the first 10minutes) FLVextract doesn't do anything except display a message under Warning/Error that reads, "Non-negative number required.Parameter name: count"

15.01.2014, 22:02

Re: Technical question,plz help

oklahoma001 wrote:<snip>
Thanks for the help but still no success. I tried another file this time(over 2.5 hours long, stops playing at the 59minute mark) and when trying to split it into 58 minute files I was left with two videos. One that was 58 minutes long and one that was 1 minute. MKVmerge didn't report any warnings or errors. I then set the duration at 60minutes (past the corrupt mark) and it created one file, 59 minutes long. Because MKVmerge didn't report any errors maybe I need to input new timestamps/duration into the flv? As in, maybe all these programs think these files are perfectly fine and are stopping at the corrupt mark because they think the file ends there.

OK Next thing to try is to use flvextract to produce elementary streams, Video,audio and time codes. Have a look at the time codes file (it will be a long text file) for any inconsistencies, i.e. time jumps forward or back or big breaks in sequence. If nothing obvious then remux using video and audio, not timecodes with Mkvmerge.

15.01.2014, 19:54

Re: Technical question,plz help

Shirtfull wrote:Try Mkvmerge, Under Global tab, split file into smaller parts by time and/or size. Info on file problem might appear in warning/error panels during remuxing, Then append good files ignoring bad file,to new file.
Thanks for the help but still no success. I tried another file this time(over 2.5 hours long, stops playing at the 59minute mark) and when trying to split it into 58 minute files I was left with two videos. One that was 58 minutes long and one that was 1 minute. MKVmerge didn't report any warnings or errors. I then set the duration at 60minutes (past the corrupt mark) and it created one file, 59 minutes long. Because MKVmerge didn't report any errors maybe I need to input new timestamps/duration into the flv? As in, maybe all these programs think these files are perfectly fine and are stopping at the corrupt mark because they think the file ends there.

15.01.2014, 07:54

Re: Technical question,plz help

oklahoma001 wrote:<snip>.

I've exhausted my limited knowledge of ffmpeg (extracting the video stream, converting the video, skipping over specific frames) and I've not made any progress. I've tried avidemux and xmediarecode and like ffmpeg neither could get past the corrupt mark. Any ideas?

Try Mkvmerge, Under Global tab, split file into smaller parts by time and/or size. Info on file problem might appear in warning/error panels during remuxing, Then append good files ignoring bad file,to new file.

15.01.2014, 05:10

Re: Technical question,plz help

brudgon wrote:i don't know if is the right place to post this questionBlush
anyway....i use media player classic for save the thumbnails but maybe there is another way to do this?
thanks for helpBlush

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14.01.2014, 21:55

Re: Technical question,plz help

Okay, so here's my problem. Bear with me as I attempt to to explain it.
I've been making my way through my .flv's from December and I've come across several files that appear to be corrupt. As I understand it, if a video is corrupt it will not play at all or play up to a certain point and freeze, sometimes crashing the video player. And sure enough when playing these files with VLC, they crash as I would expect. However, and this is the odd bit, all the files are playable with MPC-HC if I skip over the corrupt frames.

For example, one file is over 6 hours long and will only play up to the 8 minute 43 second mark in VLC before jumping to the very end, bypassing everything in the middle. If I play that same file in MPC-HC, it will do the same as VLC however if I jump ahead 5 seconds from 8 minutes 40 seconds to 8 minutes 45 seconds (in effect bypassign the corrupt mark) the file will continue to play without issue. And that goes for the half dozen files I've come across.

I've exhausted my limited knowledge of ffmpeg (extracting the video stream, converting the video, skipping over specific frames) and I've not made any progress. I've tried avidemux and xmediarecode and like ffmpeg neither could get past the corrupt mark. Any ideas?