HandBrake

Thanks! I've just checked in some amendments to the 5.1 code: Minor amendments to 5.1 audio support: * ensuring that non-AAC audio formats always use a stereo mix (rather than mono) * ensuring that Dolby Surround (Pro Logic) source is passed through as Dolby Surround (Pro Logic), and not mixed down ...

Hi golias,

I've never seen a DTS-only DVD - could you give some examples of the ones you have seen?

I don't think there's a good DTS-decoder library we could use in mediafork, but it might be possible to do DTS passthrough to an AVI.

Preliminary version just checked back in. Adds a new command line option to MediaForkCLI to preserve 5.1 audio as a 6-channel AAC when using FAAC to encode the audio. The option is "-6" or "--surround". See what you think!

Hi exodar / jbrjake, It looks like you may both be right. If iTunes Store movies are shipping with Dolby Pro-Logic rather than either Dolby Digital or 5.1 AAC, then it looks likely that Pro-Logic is the way Apple are taking things. From looking at the code, then, it looks as though Handbrake is alre...

Hi Exodar, That's interesting! Good find on the Movies FAQ. It does rather sound as though they may be going for Dolby Pro-Logic rather than Dolby Digital. This would mean it would help if Handbrake could either preserve existing Pro-Logic tracks, or encode 5.1 into Pro-Logic if possible. I'll look ...

Hi Mirkwood, Sorry, been away on business for a few days. I'll investigate this further over the next few days, as I have been working off a grab of the main trunk I took a little while back, rather than setting up svn here and checking which version I've been basing things on. I've got another ques...

Sorry, my mistake - you're completely right. Forget I mentioned avi/aac. I've been trying some tests here, to see if the 6-channel-ness makes a difference for memory usage. It doesn't seem to. The known memory leakage is present when encoding to mp4/aac, but doesn't seem to be affected by the number...

A few thoughts: It's always possible that titer wanted to make a few changes to HandBrake for his own personal use, and did so on the svn he already had set up (for speed and convenience). It might be that that's all we're seeing. I don't think it changes these discussions, however. This project sho...

My memory usage shot up to over 2 gigs within 10 minutes. I'm seeing memory usage leaks when using mp4/aac, but not when using avi/aac, so I think I've coded it to not use masses of memory (and the mp4/aac leaks are presumably the ones you already know about from the ffmpeg side of things). Part of...

Hi dynaflash, Yep, this is all in an mp4 :) I haven't checked the memory usage yet, but next time I'm testing it I'll see what it comes out as. On the short test movie I used it didn't seem horrendous - but then it's a short test movie. There is one bit of (rather major) bad news, and that is that I...

Right - with a bit of hard-coding of 6-channel audio (for now, for testing only) I seem to have Handbrake creating a 5.1 aac track as part of an mp4 The channel mapping isn't right yet, but I'm working on that next.

Any ideas on how I should best store and retrieve the number of channels?

In 0.7.1, a pointer to an audio struct used to be passed over to the work threads for each decoder / encoder, and I was using this to track the detected number of channels, so that the decoder / encoder work threads could use the right number of channels. Unfortunately, this seems to have been remov...

Okay, so I've answered my own question just now. Turns out that I was doing the right thing all along, but the QuickTime bug mentioned by Ritsuka (which affects Intel only) was causing QuickTime to crash when trying to parse multi-channel mpeg4 files. So I should be able to test under Rosetta and ge...

Jbrjake, So what did you change to make handbrake output a file that shows up as 5.1 in QuickTime? I've tried all kinds of permutations, and no matter what I do, whenever I open the movie in QuickTime Player and try and view the movie's audio properties, QT Player crashes. Something is definitely wr...

Yep, I've been amending the code based on your post, and have made lots of progress on converting the innards of Handbrake to respect channel count. After a bit more research, I think the problem actually lies with muxmp4 using mp4.h (I've been working on the original 0.7.1 source). I see that this ...

Thanks for the tip. I've made some good progress with changing the innards of the 0.7.1 source to support multichannels, and have got my head round things a bit more now. The big problem I'm having is that libfaac doesn't seem to be geared up for creating 5.1 aac files. At least, I can't find the se...

So even if we can get 5.1 sound in a playable wrapper format (most likely .mov rather than .mp4), the user will need an actual 6-channel soundcard rather than just being able to use the digital output in all new Macs. I take that back! If I play one of Apple's 5.1 HD trailers (The Simpsons Movie HD...

Hi Aaron, That's a pain if true. It might be a case of adding some extra info to the mp4 file, but I note that all of Apple's high-def 5.1 trailers are .mov files too. I'll try and verify if this is categorically the case. There's another problem too (suggested by the page you linked to). As I under...

By decode or output, are you referring to how QuickTime has never been able to send discrete AC3 out, instead decoding it to 2-channel? I'm doubtful @tv will support it any better...though it would be awesome. Just to be clear, QuickTime doesn't ship with an AC3 decoder component. QT7 definitely su...

After a bit of experimentation, I'm feeling pretty confident about setting the right settings for the decoder / encoder, but I'm struggling to get my head around the buffers and lists, and how they need to change to deal with variable-sized audio data (rather than always-stereo data). Can anyone giv...

No worries! I've been a bit surprised today that I couldn't find a tool out there to do what I needed - I think there's a general perception that 5.1 is a lot harder to do than it actually is in QuickTime. Certainly with QT7 there are all kinds of possibilities, but every tool out there seems geared...

D'oh - I got it working by modifying Jamfile. I see how it works now. Apologies!

Hi there, I've been trying to solve this myself today, and wondered if I can help... I'm new to the HandBrake dev forums, but I'm a QuickTime audio programmer with very good experience of channel mapping etc. Happy to help out if I can! If Handbrake creates a 6-channel AAC track within an MP4, and l...