ffmpeg convert from mkv to mp4 [matroska,webm @ 0x1d06640] Read error at

[blurry]

for example I downloaded some film, it is somehow encoded with some program, when I try to use ffmpeg to convert it, let's say from mkv to mp4, i get an error that:

[matroska,webm @ 0x1d06640] Read error at pos. 2241497 (0x2233d9)

now how can I know where is the reason that this happens? should just avoid this kind of files, or somehow debug it and see what is the reason behind this error? or maybe skip this error frames, but i dont know how many frames may be like this, what if most of the file is filled with corrupted frames, altough it is playable in the video player

[pandy]

You can try to force ffmpeg to ignore errors - add bellow to your commandline

-err_detect ignore_err -ec guess_mvs+deblock+favor_inter -ignore_unknown

I would advise to reencode your source so output will have corrupted content but will be correct from syntax perspective.

[blurry]

You can try to force ffmpeg to ignore errors - add bellow to your commandline

-err_detect ignore_err -ec guess_mvs+deblock+favor_inter -ignore_unknown

I would advise to reencode your source so output will have corrupted content but will be correct from syntax perspective.

after trying this commands:

[matroska,webm @ 0x1789580] Read error at pos. 2241497 (0x2233d9)
[h264 @ 0x28aaee0] error while decoding MB 45 33, bytestream -11
[h264 @ 0x28aaee0] concealing 964 DC, 964 AC, 964 MV errors in B frame
frame=  191 fps= 18 q=-1.0 Lsize=     934kB time=00:43:40.12 bitrate=   2.9kbits/s    
video:558kB audio:372kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.478487%
[libx264 @ 0x17d5720] frame I:3     Avg QP:14.47  size:  8780
[libx264 @ 0x17d5720] frame P:99    Avg QP:17.68  size:  5154
[libx264 @ 0x17d5720] frame B:89    Avg QP:14.18  size:   381
[libx264 @ 0x17d5720] consecutive B-frames: 33.0% 14.7%  0.0% 52.4%
[libx264 @ 0x17d5720] mb I  I16..4: 51.4% 44.1%  4.5%
[libx264 @ 0x17d5720] mb P  I16..4:  2.9%  6.8%  0.1%  P16..4: 23.0%  3.1%  3.1%  0.0%  0.0%    skip:61.0%
[libx264 @ 0x17d5720] mb B  I16..4:  0.0%  0.0%  0.0%  B16..8:  5.0%  0.1%  0.0%  direct: 0.1%  skip:94.7%  L0:39.8% L1:58.6% BI: 1.6%
[libx264 @ 0x17d5720] 8x8 transform intra:63.4% inter:85.2%
[libx264 @ 0x17d5720] coded y,uvDC,uvAC intra: 20.2% 24.4% 4.2% inter: 5.0% 6.7% 0.2%
[libx264 @ 0x17d5720] i16 v,h,dc,p: 59% 20% 10% 11%
[libx264 @ 0x17d5720] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 24% 13% 53%  2%  2%  2%  2%  1%  1%
[libx264 @ 0x17d5720] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 40% 19% 22%  4%  5%  3%  4%  2%  2%
[libx264 @ 0x17d5720] i8c dc,h,v,p: 80% 10%  9%  0%
[libx264 @ 0x17d5720] Weighted P-Frames: Y:21.2% UV:18.2%
[libx264 @ 0x17d5720] ref P L0: 56.8% 13.1% 20.7%  8.4%  1.1%
[libx264 @ 0x17d5720] ref B L0: 79.9% 17.9%  2.2%
[libx264 @ 0x17d5720] kb/s:1.74

after converting the output video, the file size is too low and it just stops while playing at some point and thats it,

I've tried to reencode it to the same container mkv, but got the same errors

tried to reencode wit this command:

ffmpeg -err_detect ignore_err -ec guess_mvs+deblock+favor_inter -i "film.mkv" -c:v libx265 -preset ultrafast -x265-params lossless=1 test.mkv

output:

[matroska,webm @ 0x1e94ba0] Read error at pos. 2241497 (0x2233d9)
[h264 @ 0x2853500] error while decoding MB 45 33, bytestream -11
[h264 @ 0x2853500] concealing 964 DC, 964 AC, 964 MV errors in B frame
[matroska @ 0x1efe6c0] Starting new cluster due to timestampitrate=   0.2kbits/s    
frame=  191 fps= 17 q=0.0 Lsize=   18850kB time=00:43:40.11 bitrate=  58.9kbits/s    
video:18664kB audio:172kB subtitle:0kB other streams:0kB global headers:8kB muxing overhead: 0.074325%
x265 [info]: frame I:      1, Avg QP:4.00  kb/s: 230.17  
x265 [info]: frame P:     48, Avg QP:4.00  kb/s: 21305.16
x265 [info]: frame B:    142, Avg QP:4.00  kb/s: 18611.59
x265 [info]: consecutive B-frames: 2.0% 2.0% 0.0% 95.9% 
x265 [info]: lossless compression ratio 9.21::1
encoded 191 frames in 11.48s (16.63 fps), 19192.27 kb/s, Avg QP:4.00

how should I correctly reencode it?, cause even ignoring errors wouldn't help

video source info by the way:

Video
ID                             : 1
Format                         : AVC
Format/Info                    : Advanced Video Codec
Format profile                 : High@L3.1
Format settings, CABAC         : Yes
Format settings, ReFrames      : 5 frames
Codec ID                       : V_MPEG4/ISO/AVC
Bit rate                       : 4 000 Kbps
Width                          : 1 280 pixels
Height                         : 720 pixels
Display aspect ratio           : 16:9
Frame rate                     : 23,976 fps
Color space                    : YUV
Chroma subsampling             : 4:2:0
Bit depth                      : 8 bits
Scan type                      : Progressive
Writing library                : x264 core 148 r2721
Encoding settings              : cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x3:0x132 / me=umh / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=6 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=239 / keyint_min=23 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=abr / mbtree=1 / bitrate=4000 / ratetol=1.0 / qcomp=0.60 / qpmin=5 / qpmax=69 / qpstep=4 / vbv_maxrate=8000 / vbv_bufsize=17500 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=3:1.00
Default                        : Yes
Forced                         : No
Color range                    : Limited
Color primaries                : BT.709
Transfer characteristics       : BT.709
Matrix coefficients            : BT.709
DURATION                       : 00:44:08.693000000

[pandy]

It look to me like corrupted storage or seriously corrupted file, beyond listed position ffmpeg is unable to find any useful data...

[LigH.de]

IMHO, quite obviously your video source is defect, and ffmpeg is unable to decode beyond this point, so it seems to be a larger corruption.

Different decoders have a different "error resilience"; if ffmpeg can't skip the corrupt part safely, maybe other applications (VLC player - yes, it can convert too; Avidemux) or some AviSynth decoders can (FFMS2, L-SMASH Works, DSS2Mod with LAV Filters, and DirectShowSource as the last hope).

[T-dawg]

I was using Handbrake and Format Factory back in a day for that. You can also try WALTR if you wanna watch the movie on Apple devices.

[LigH.de]

Please note the warning that Format Factory may mess up your system by installing "Possibly Unwanted Programs" (ad-supported freeware).