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Raw Video / Re: Is MLV all that it's cracked up to be?
« on: March 07, 2014, 05:29:59 PM »Post-processing:
These post-processing tools are not developed by ML, other than some reference implementations (raw2dng/mlv_dump), which are command-line tools to keep them simple.
The programs you are talking about are developed by other authors (not by ML devs), so their authors will most likely welcome your feedback.
Recording modules
Judging from user feedback, my impression is that raw_rec is pretty much stable (except for some small quirks), but minimalist (no sound, no metadata), and mlv_rec is still work in progress, has the big advantage of audio recording, but write speeds are a bit inconsistent, and being quite a bit more complex, there are more things likely to break. However, it's designed to be extensible (friendly for future development), which can't be said about the RAW format.
An example regarding extensibility: suppose you may want to do some FPN correction, and for that you need to record optical black data (either complete or summarized somehow) or some sort of bias or dark frames. With the RAW format, you have no other choice but creating external sidecar files. With MLV, you can simply add this optical black data to MLV spec and implement it. The converters that don't know about this new feature will simply ignore it gracefully (this is allowed by the design of MLV format); the ones that do will use this correction data and output better images.
Once mlv_rec will be better in all aspects, raw_rec will most likely go away. For now, my impression is that it isn't there yet, so I still keep the old raw_rec in the nightly builds.
The cause of pink frames is not yet fully understood, and recent versions of mlv_rec were reported to have fewer pink frames at least on 550D. On other cameras, raw_rec may be better, I don't know.
If you report things like one module seems to be more solid during long usage, a useful feedback should include some statistics. For example, say you've recorded a bunch of footage at settings XYZ, and got 15 pink frames out of 12345. Then, say you've changed setting Y and got 30 pink frames out of 1234. This feedback is much better than vague reports about intermittent failures, but providing a way to reproduce a bug is even better.
I use the camera primarily for photos, so I didn't actually use the raw recorders in the last few months.
Probably quite easy, but since the MLV file format is extensible, I don't expect further development on raw_rec (other than maybe some basic maintenance), but anybody is free to give it a try.
I don't exclude a lite version of mlv_rec at some point in the future, rewritten with performance and robustness in mind, rather than feature-completeness. But I'm confident that MLV as file format is here to stay.
First of all thanks for Devs getting involved in this thread , there are answers that I would like to pose.
RAW_REC to me seems pretty stable too, however for the application I need I need sound as I only have 2 people involved in the project I would love to record in RAW.
MLV_REC is conceptually great, however the recording speeds/buffer performance is very up and down. Im working on a cooking show for web distribution 24p is not the look I need at all. the motion blur is too filmic, 30P would be ideal. If card spanning can return to full HD 30p with MLV and MLV_SND I will be a very happy man. I will also feel that ML has achieved a a fully fictional raw video camera with sound, a real video camera so to speak, a complete functional unit to rival video cameras. In post this means I can use Pluraleyes to auto sync external professional sound, reducing post processing time.
Is it too early to say if 30P full HD will be possible?
Is there any way you could explain what is going on with the write speeds to a laymen, Im big on solving problems but just unfortunately not coding ones. I built a shoulder rig to film the show and be able to start and stop recording, and audio recording all while the camera is on my shoulder. I built the rig with the fact a 5D mkiii might not acutaly be the camera to do this project, so the baseplate can be changed and as such the camera. However the canon sensor is amazing and produces superb skin tones and colors in my opinion much better that say a Gh3 or Black Magic (Subjective I know, lets not start another fight here)
I would just love to see this project done on MLV_REC and MLV_SND at 30P does anyone think that is possible in the future?
