In my recent work, I encountered a rare case of damaged video files. This video was recorded by a Panasonic S1R camera, and the MDT file was damaged due to a dead battery. Although there are many cases of repairing MDT to MOV or MP4 video files, this video file has a special feature, which increases the difficulty in repairing. We might as well analyze the difficulty.
From the perspective of video encoding, video encoding AVC, 150M bit rate, 4K image quality, these are nothing special, they are all common parameters of video file repair technology. But looking at the audio parameters audo, Code ID, LPCM, there is a little difference. If you have audio work experience, you can see that the sound quality of LPCM is the uncompressed original sound recording. Compared with the compressed audio coding that was repaired in the past, this repair is somewhat difficult. Try to use the previous repair code, open the repaired video, the picture quality is normal, but there is no sound or noise. This is video decoding, and audio cannot be decoded correctly. Therefore, according to the audio coding characteristics of LPCM, the existing repair programming is updated, and the support for LPCM is added to solve this problem. The following parameter data of video encoding can be used for repair reference.
| General | |
| Format | MPEG-4 |
| Format profile | QuickTime |
| Codec ID | qt 2011.07 (qt /pana) |
| File size | 138 MiB |
| Duration | 7 s 7 ms |
| Overall bit rate mode | Variable |
| Overall bit rate | 165 Mb/s |
| Video | |
| ID | 1 |
| Format | AVC |
| Format/Info | Advanced Video Codec |
| Duration | 7 s 7 ms |
| Bit rate mode | Variable |
| Bit rate | 150 Mb/s |
| Maximum bit rate | 180 Mb/s |
| Width | 3 840 pixels |
| Height | 2 160 pixels |
| Audio | |
| ID | 2 |
| Format | PCM |
| Format settings | Big / Signed |
| Codec ID | lpcm |
| Duration | 7 s 7 ms |
| Bit rate mode | Constant |
| Bit rate | 2 304 kb/s |
| Channel(s) | 2 channels |
| Channel layout | L R |
| Sampling rate | 48.0 kHz |
| Bit depth | 24 bits |
| Stream size | 1.92 MiB (1%) |
