Converting DVD to x264 mp4 with Handbrake: how to preserve 5.1 audio?

[Radio Radio]

So I've been testing out converting a DVD movie to a x264 mp4 with Handbrake, but the times I've tried out conversion, the resulting file has stereo audio (and the source DVD is 5.1 audio). Which audio settings should I choose if I want to preserve the 5.1 audio for the mp4 file?

[aedipuss]

you might try vidcoder, it's a gui frontend for handbrake with easier to use settings. it has ac3 passthrough or aac 5.1 mixdown in the audio tab settings.

[Radio Radio]

Thanks for the tip aedipuss. After looking at the Handbrake settings, I realize now I'd been using the aac 5.1 mixdown and not the ac3 passthrough. I'm assuming ac3 passthrough will give me what I want - preserved 5.1 audio in my converted video file.

[jagabo]

Leave the AC3 passthrough track in the Audio tab. Remove the AAC encoded track if necessary.

[Radio Radio]

Thanks jagabo, ill try that.

[jagabo]

Keep in mind that Handbrake will produce an M4V file, not MP4. It's really the same thing but the M4V extension helps programs understand the file has AC3 audio, not AAC.

[Radio Radio]

Keep in mind that Handbrake will produce an M4V file, not MP4. It's really the same thing but the M4V extension helps programs understand the file has AC3 audio, not AAC.

Ahhh I see. So even though it gives the option of the file container as "mp4", the result is an m4v. Good to know.

[Selur]

but the M4V extension helps programs understand the file has AC3 audio, not AAC.

Curious, I know iTunes missuses the m4v extension (normally ment for MPEG-4 video streams), but what tool uses 'm4v' instead of 'mp4' to identify whether the audio is 'ac3' or 'aac'?

[jagabo]

but the M4V extension helps programs understand the file has AC3 audio, not AAC.

Curious, I know iTunes missuses the m4v extension (normally ment for MPEG-4 video streams), but what tool uses 'm4v' instead of 'mp4' to identify whether the audio is 'ac3' or 'aac'?

I don't use any Apple products so I can't tell you. But I believe it's to prevent devices that don't support AC3 audio from playing the files. Or at least from trying to play the audio.

[Selur]

Ah, okay, it sounded like you knew programs who do use the extension as some sort or identification marked,..

[DarrellS]

but the M4V extension helps programs understand the file has AC3 audio, not AAC.

Curious, I know iTunes missuses the m4v extension (normally ment for MPEG-4 video streams), but what tool uses 'm4v' instead of 'mp4' to identify whether the audio is 'ac3' or 'aac'?

I don't use any Apple products so I can't tell you. But I believe it's to prevent devices that don't support AC3 audio from playing the files. Or at least from trying to play the audio.

That's why I convert everything to H264/AC3 MKV. I try to avoid MP4 whenever possible. I'll use a ffmpeg batch file to put H264/AAC FLV in a MP4 container since that seems to be the preferred internet file type these days and they've already destroyed the original AC3 audio. I haven't used Handbrake in a while but I would probably recommend it for users that want a quick and easy program and don't want to learn how to use Virtualdub although Selur's Hybrid program looks like a very good option. Probably a little harder to use than Handbrake but has a lot of different encoders to use.

[jagabo]

I try to avoid MP4 whenever possible.

Same here.

[Selur]

*gig* I normally try to avoid mkv. So very one get's it's poison.

[Radio Radio]

I have another question about handbrake, (again, im assuming it better to just keep it in this thread then to make a new one). So I did a conversion for a movie of about 100 minutes in length, constant quality at an RF of 19, the file size came out to be just under 700mb. I checked the file with Media Info and it says the video bittrate is around the 500 mark which seems kind of low but im new to this converting stuff, so curious if thats an ok video bitrate

[Selur]

look at the quality if the quality is okay, the bitrate is too, otherwise: No

[Radio Radio]

Ok, one last question. Is there a way to cut a small clip out of a m4v as a "sample" scene (obviously, a way to do it without re-encoding)

[poisondeathray]

Ok, one last question. Is there a way to cut a small clip out of a m4v as a "sample" scene (obviously, a way to do it without re-encoding)

One way is using ffmpeg

Use -ss for start time and -t for duration

e.g

ffmpeg -input.m4v -vcodec copy -acodec copy -ss 00:00:05 -t 00:00:10 output.m4v

This would copy a clip from 5 sec to 15 sec running time , for a total length of 10 seconds

[Radio Radio]

Ok, one last question. Is there a way to cut a small clip out of a m4v as a "sample" scene (obviously, a way to do it without re-encoding)

One way is using ffmpeg

Use -ss for start time and -t for duration

e.g

ffmpeg -input.m4v -vcodec copy -acodec copy -ss 00:00:05 -t 00:00:10 output.m4v

This would copy a clip from 5 sec to 15 sec running time , for a total length of 10 seconds

awesome, exactly what im looking for. thanks poisondeathray!

[jagabo]

ffmpeg -input.m4v -vcodec copy -acodec copy -ss 00:00:05 -t 00:00:10 output.m4v

Does it cut on the nearest key frames? Or does it leave partial GOPs?

[poisondeathray]

ffmpeg -input.m4v -vcodec copy -acodec copy -ss 00:00:05 -t 00:00:10 output.m4v

Does it cut on the nearest key frames? Or does it leave partial GOPs?

Cuts on keyframes only


So Radio Radio - the cuts won't necessarily be frame accurate

[jagabo]

ffmpeg -input.m4v -vcodec copy -acodec copy -ss 00:00:05 -t 00:00:10 output.m4v

Does it cut on the nearest key frames? Or does it leave partial GOPs?

Cuts on keyframes only

Thanks. I should use it more often!

[Kblev]

Hi all,
I have a library of dvd's. If you convert a movie on your HDD that is in TS folders, VOB files, and you want to compress it for space savings down to roughly a gig., and the audio is in ac3, or dts, what format will keep it just as good, if possible? Will I lose quality and/or 5.1? I have a couple different softwares and they won't allow me keep the same audio codec.
Thanks