MJPEG Audio Sample Rate and Bitrate on GF1 (maybe other cameras too)

DidiEdd

Hey there, thanks for the ptool hack Vitaly, I've been using it for over half a year now and I'm finally starting to realize its full potential on my GF1 after understanding more about cameras and picture/video data in general, so it's been a big help in regards to my camera hobby, specifically with recording video on a camera not-so-good for video.

But eventually I realized a minor issue as well. This is regarding the audio of MJPEG (on GF1, but maybe other cameras as well). For some reason, when recording MJPEG, the audio bitrate is just okay at 256/257/268/281 kbps. However, the worse issue is that it is being captured at 16,000 samples per second, which is an issue because essentially any frequency past 8 KHz cannot be recorded to the video... With AVCHD Lite, the audio is successfully recorded at a high bitrate of 448 kbps, but even more importantly, the sample rate is 48,000 Hz which can capture frequencies up to 22 KHz safely. I want to make use of MJPEG at times, but with this knowledge I have to be careful not to use it in situations where the audio could be important (considering I have to use my phone as an external mic). It takes time to get my other audio sources running, so in a "quick, record!" moment, I wouldn't want to be forced to use AVCHD Lite in a situation where I would've preferred to use MJPEG, just because the audio will be poor for the time it takes to enable my external audio recording setup.

From what I've seen on the site nowadays, I've gathered that you've done something along the lines of "retiring" from this ptool project, so I understand if there's nothing you can do, but if possible, couldn't there be any way we could get the sample rate fixed to 48 KHz for MJPEG and not just AVCHD? Additionally, for the bitrate settings to affect MJPEG as well, not just AVCHD. Thank you for your time.

endotoxic

I’m the beginning the mjpg was the first implementation to have proper image quality from the hack, but was never intended from a manufacturing point of view to have good audio, it was ‘’the bad codec’ avchd lite was the codex to use. I suggest using the avchd hacks. The only benefit of using mjpg was its ability to change the resolution very easy to wired formats and attain stability.

endotoxic

Ohhh is gf1 hmmm maybe mjpg may be the better option. Use a microphone to record better audio maybe that helps.

DidiEdd

I appreciate your reply

I use my phone as an external stereo microphone, but it takes time to set it up and turn it on, so I don't want to rely on extremely poor audio for the time the audio isn't recorded by the phone, in the case of starting to film something immediately. I also want peace of mind knowing that the audio isn't totally screwed if I had something go wrong with my phone and the audio doesn't record properly (accidentally recorded 16KHz mono on my phone before... that hurt), and at least comparable to the audio bitrate hack on the AVCHD Lite codec, I would hope to get usable audio out of it if necessary. Before the hack, actually even the AVCHD Lite codec had poor audio quality due to a low bitrate, and I thought that was just the cheap built-in mic, but the increased audio bitrate really improved the retention of detail in the audio and allows me to better enhance it. So I'm really hoping to have that MJPEG's audio as a backup just in case something happens. Of course, if this is some kind of data transfer speed limitation why it wasn't added then I understand, but just figured that probably isn't the case if AVCHD Lite can be used at a pretty high bitrate for both audio and video as well.

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