(How) do you re-encode movies?

[Jon Ruyle]

The question on time lapse got me thinking that my ways of processing movies from the 5DII are not very good. (The movies that come directly off the 5DII are unplayable on my computer because they have too high a data rate and my computer is too slow. So I convert them from huge .MOV files to much smaller .avi files)


I have a couple of ways I do it now, but neither is good. I use Rad video tools, but I have to convert one movie at a time. Or mencoder, but that is a little hard to use. I want something that can do batch processing easily, preferably with a gui, where I can just say "convert all movies in such and such directory and call me in the morning" kind of thing.


Anyone have a better way? Or do you all have computers that are so fast you can just play giant .MOV files directly?

[wickerprints]

You are not obligated to record in 1080p with the 5D Mark II. You can select 640x480 which will dramatically reduce the file size and playback requirements. If for some reason you need 1080p resolution, then reducing the file size by re-encoding at a lower bit rate defeats the purpose of capturing that resolution to begin with.


Re-encoding is a very computationally expensive task. You must decode the input stream, then encode this data, possibly with a different algorithm. Therefore it is often slower than playback.

[Jon Ruyle]

I like it in 1080p. It looks a lot better than 640x480 IMO.


The 5DII does a lousy job of compressing- for exactly the reason you mention: doing a reasonable job is computationally expensive. I've been using programs that do a good enough job of compression and give me small files my computer can actually play (they are slow but I don't mind that).

then reducing the file size by re-encoding at a lower bit rate defeats the purpose of capturing that resolution to begin with.

Not at all. Using decent compression, one can get very good looking 1080p (far better than most satellite HD I see out there) video with a substantially lower data rate than what the 5DII produces.


My problem is that the program I use has a rather crummy interface... I thought everyone but me must be using something way better []

[Jon Ruyle]

Ugh, duplicate. Sorry.

[wickerprints]

I like it in 1080p. It looks a lot better than 640x480 IMO.


The 5DII does a lousy job of compressing- for exactly the reason you mention: doing a reasonable job is computationally expensive. I've been using programs that do a good enough job of compression and give me small files my computer can actually play (they are slow but I don't mind that).

That is at the very least misleading. Video compression is a balance between data size versus image quality. If Canon utilized higher compression ratios, you would be assured that people would then complain that the recorded footage was of inferior quality and had too many artifacts. As it is, we already have hordes of people complaining that the 5D2 doesn't record 24p, and of the "jello effect." So your statement implying that Canon made the files unnecessarily large because the Digic processor is too slow is factually incorrect. Digic IV can easily utilize a higher H.264 compression ratio with a corresponding lower bitrate. But one cannot recover information once it is thrown away


When the source device is processing input video, it does so through optimized hardware. Digic IV is such a processor. It is not like a computer's CPU, which is a general-purpose processor that utilizes software code to do the hard work of video encoding and decoding.

Not at all. Using decent compression, one can get very good looking 1080p (far better than most satellite HD I see out there) video with a substantially lower data rate than what the 5DII produces.

If you are happy with the resultant image quality for your hardware playback capabilities, then that's great. But unfortunately, you have no other options. If you want a lower bitrate straight out of the camera, Canon is extremely unlikely to support it via firmware (again, it is not a question of whether the hardware is capable of it, because it is). If you want smooth playback at high bitrates, or faster encoding/transcoding, get a faster machine.

My problem is that the program I use has a rather crummy interface... I thought everyone but me must be using something way better [img]/emoticons/emotion-1.gif[/img]

Most people who are editing 5D2 footage are doing so via a variety of prosumer/professional solutions on modern hardware, such as Final Cut Studio. They have sufficient hard drive capacity and performance so that they don't need to recompress. Some in fact complain that the choice of codec (H.264) leads to *too aggressive* compression, and that they would have preferred native recording to a less lossy format. So you need to understand that in the world of video, one size does not fit all.

[Jon Ruyle]

Video compression is a balance between data size versus image quality.

But there is also good and bad compression. With DivX, for example, you can get far better video quality than DVD at the same data rate.

So your statement implying that Canon made the files unnecessarily large because the Digic processor is too slow is factually incorrect.

I didn't say the 5DII makes files unnecessarily large. If the 5DII was 100 times as fast as it is, it could do a better job. But it isn't. That is okay. I'm not mad at the 5DII. (Okay, okay, I said "it does a lousy job" compressing... but that is because it has to do it real time, not because the 5DII is lame).

If you are happy with the resultant image quality for your hardware playback capabilities, then that's great. But unfortunately, you have no other options. If you want a lower bitrate straight out of the camera, Canon is extremely unlikely to support it via firmware (again, it is not a question of whether the hardware is capable of it, because it is). If you want smooth playback at high bitrates, or faster encoding/transcoding, get a faster machine.

I don't want a lower bit rate straight out of the camera. I like the 5DII the way it is. And mencoder does a fine job producing video that is satisfactory to me and plays fine on my computer. Encoding is 100 times slower than real time, but that is okay. I was just hoping for something with a more convenient interface. (mencoder has an okay interface if you don't mind writing shell scripts... I'd prefer not to).

Most people who are editing 5D2 footage are doing so via a variety of prosumer/professional solutions on modern hardware, such as Final Cut Studio.

Isn't final cut studio about $1000? I'm looking for something about $1000 cheaper than that []


Keep in mind, I don't want to fancy editing. I just want to do what free programs like mencoder do, but with an easier to use interface.

So you need to understand that in the world of video, one size does not fit all.

Yeah, I know that. I'm just looking for the size that fits *me*. Maybe it doesn't exist.

[wickerprints]

Well, now with H.264 -> DivX, you're talking about transcoding, not just re-encoding. Those are entirely different things. If you want to transcode to a more...compact format, then there's just no way to avoid doing it post-capture.


Different codecs exist for different purposes. DivX is not a good editing format. (Many will point out that H.264 isn't, either!) However, editing formats tend to have large data sizes, so presumably Canon chose H.264 as a tradeoff between what one could record on, say, a "tiny" 32GB CF card, versus something with minimal artifacts and optimal post-production properties.


All that said, I think if editing is not your goal but rather straight-up transcoding, then a simple program like HandBrake (I think it's Mac only?) can do what you want. There are other free programs but as the old adage goes, you get what you pay for. Certainly FCS is overkill--not to mention your hardware has to support it. Give it a try, though. It certainly can't hurt.

[Daniel Browning]

Anyone have a better way?

Personally, I can't fathom why you'd think anything could be better than a shell script. [] But since you insist, I use and recommend Cineform NeoScene ($99 from videoguys.com). Not only does it have an excellent UI for batch conversion, but it gives you a destination codec that is far better than whatever else you are using now, and makes editing fast and easy.


A free alternative might be MPEG Streamclip. I've used it to convert 5D2 MOV files. You don't get any good codecs, but it does batches.

[Jon Ruyle]

Thanks, Daniel and wickerprints. I'll look in to the programs you suggested.

Personally, I can't fathom why you'd think anything could be better than a shell script. [img]/emoticons/emotion-5.gif[/img]

I don't think I'll find anything *better*. I just want something requiring less effort on my script-impaired part.