Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
Bernhard Praschinger wrote: > Hallo > > >>However, I've already done the hard work in my DVD-Audio authoring >>application, so I will try and copy-and-paste together a "wav2lpcm" >>program that supports 16-bit and 24-bit samples. I'll add 20-bit when >>I've worked out how they are stored - I'm assuming there's even less >>demand for 20-bit than 24-bit. > > That would be nice, and even nicer if it supports reading the stream > from stdin so you can create your lpcm streams in a single step from the > AVI/QT file. I've just released the first version (see the email I have just sent to this list). You can use "/dev/stdin" as the input filename to read from stdin if you wish. Output is always written to stdout. Dave. --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
On Apr 5, 2005 1:06 PM, Bernhard Praschinger <[EMAIL PROTECTED]> wrote: > > BTW: Does it make sense, when you convert the bitrate, from 44.1kHz > 16Bit to 48/96kHz that you increase also the audio sample depth to 20 or > 24 bit when resampling ? To be able to reconstruct the waveforme more > exact. > No it does not make sense. Sample rate doesn't affect the accuracy of reconstruction below the Nyquist frequency. Practically, you might want to increase the bit depth *before* doing the conversion if you are concerned about rounding errors in your resampling algorithm. Regards, Mark [EMAIL PROTECTED] -- You think that it is a secret, but it never has been one. - fortune cookie --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
Hallo > However, I've already done the hard work in my DVD-Audio authoring > application, so I will try and copy-and-paste together a "wav2lpcm" > program that supports 16-bit and 24-bit samples. I'll add 20-bit when > I've worked out how they are stored - I'm assuming there's even less > demand for 20-bit than 24-bit. That would be nice, and even nicer if it supports reading the stream from stdin so you can create your lpcm streams in a single step from the AVI/QT file. BTW: Does it make sense, when you convert the bitrate, from 44.1kHz 16Bit to 48/96kHz that you increase also the audio sample depth to 20 or 24 bit when resampling ? To be able to reconstruct the waveforme more exact. auf hoffentlich bald, Berni the Chaos of Woodquarter Email: [EMAIL PROTECTED] www: http://www.lysator.liu.se/~gz/bernhard --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
On Tue, 5 Apr 2005, Dave Chapman wrote: > I've just checked the sox CVS (see http://sox.sourceforge.net) and > 24-bit support is still on the TO-DO list. To quote that file: :( > I've just started exploring 24-bit audio under Linux, and share your > feeling that very few applications support it. I don't know about the > closed-source world. It's very well supported. Most (all?) of the professional gear available handles 24bit audio - multiple 24bit streams use a lot of bandwidth and I've seen IEEE1394 used as the transport mechanism. > program that supports 16-bit and 24-bit samples. I'll add 20-bit when > I've worked out how they are stored - I'm assuming there's even less > demand for 20-bit than 24-bit. Can't say I've ever seen 20bit used but I'd think it would be a reasonable compromise on the amount of space used. DTS has less compression than AC3 and would work except that DTS encoders are quite expensive. > I'm sure lots of people would like to see WAV support in mplex, but I > don't have the time to attempt that at the moment. Shouldn't be that hard to check for the RIFF header and extract the parameters. The trickier part would seem to be doing the byte flipping and/or repacking. One thing I do wonder though is: are folks taking as much care with the video as they are with the audio? If 24bit uncompressed audio is considered necessary shouldn't video be captured/processed/rendered in 8 (or even better 10) bit uncompressed form (which in the studios means 10 bit uncompressed 4:2:2) with a final conversion to 8bit 4:2:0 at encoding time? Even using DVCPRO50 (50Mb/s 4:2:2) would be better than DV25 or MJPEG. Cheers, Steven Schultz --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
Steven M. Schultz wrote: >>I don't know if any tools exist to do this manipulation. > > > Is there a newer version of 'sox' that might do the task? I haven't > done any serious looking at audio projects but I get the feeling that > 24bit audio isn't well supported outside the professional studios > yet. I've just checked the sox CVS (see http://sox.sourceforge.net) and 24-bit support is still on the TO-DO list. To quote that file: "* Support 24-bit formats... Difficult because sometimes that means 24-bits in a 32-bit integer and sometimes it means packed 24-bits (read 3-bytes at a time)." I've just started exploring 24-bit audio under Linux, and share your feeling that very few applications support it. I don't know about the closed-source world. However, I've already done the hard work in my DVD-Audio authoring application, so I will try and copy-and-paste together a "wav2lpcm" program that supports 16-bit and 24-bit samples. I'll add 20-bit when I've worked out how they are stored - I'm assuming there's even less demand for 20-bit than 24-bit. I'm sure lots of people would like to see WAV support in mplex, but I don't have the time to attempt that at the moment. Dave. --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
On Tue, 5 Apr 2005, Dave Chapman wrote: > Unfortunately, it's not quite as simple as that for 24-bit audio. I didn't think it would be ;) Oh, you're also quite correct about flipping bytes in the 16bit lpcm files - I momentarily forgot that '-x' is needed when using sox to convert .wav to .raw > As you can see, the packing consists of the most significant 16-bits of > the four samples (in big-endian byte order), followed by the least > significant 8 bits of the four samples. Ah ha! I wondered how the bytes were packed for 24bit audio - that's another little mystery solved. Thanks. > I don't know if any tools exist to do this manipulation. Is there a newer version of 'sox' that might do the task? I haven't done any serious looking at audio projects but I get the feeling that 24bit audio isn't well supported outside the professional studios yet. Cheers, Steven Schultz --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
Steven M. Schultz wrote: > Yes, something like > > sox input.wav sox.raw > > might do the trick - but check the manpage first ;) I should also add (for completeness) that 16-bit audio requires byte-swapping when converting from WAV to a raw format. mplex also requires LPCM audio streams to have the ".lpcm" extension, so you need to manually specify the output filetype "-t raw" to sox. So a suitable sox command (for 16-bit only) is: sox input.wav -x -t raw output.lpcm If your input file isn't 48KHz or 96KHz, you can resample using, for example: sox input.wav -r 48000 -x -t raw output.lpcm resample Dave. --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
Steven M. Schultz wrote: >>i'm trying to create a dvd video with an lpcm >>soundtrack that has a sample size of 24 bits and a >>sample frequency of 48 kHz. when i run mplex: >> > >>are there problems with mplex and lpcm audio? if so, > > > No, there are not any known problems if you give mplex a lpcm audio > file. > > There are problems with a WAV files though. Strip off the WAV header > and produce a 'raw' LPCM file and it will work. Unfortunately, it's not quite as simple as that for 24-bit audio. For 24-bit audio, the method of packing of the data in the LPCM stream is different to a WAV file. I've been working on DVD-Audio authoring, and the same packing for 24-bit samples is used there (in the .AOB files). As an example, here are 12 bytes of data from a 24-bit stereo WAV file and the same data in an LPCM stream in a VOB/AOB file: WAV: 01 23 45 bf 60 8c 67 89 ab b7 d4 e3 AOB: 45 23 8c 60 ab 89 e3 d4 01 bf 67 b7 A WAV file is little-endian, so it consists of the samples 0x452301 (sample 0, left), 0x8c60bf (sample 0, right), 0xab8967 (sample 1, left), 0xe3d4b7 (sample 1, right). As you can see, the packing consists of the most significant 16-bits of the four samples (in big-endian byte order), followed by the least significant 8 bits of the four samples. The following unoptimised C code performs the above manipulation - you must ensure that the PCM data is a multiple of 12 bytes, if necessary by padding the end of the stream with an extra sample. for (i=0;ihttp://dvd-audio.sourceforge.net/ Regards, Dave. --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
Re: [Mjpeg-users] dvd with 24 bits/48 kHz audio
On Mon, 4 Apr 2005, chris wrote: > i'm trying to create a dvd video with an lpcm > soundtrack that has a sample size of 24 bits and a > sample frequency of 48 kHz. when i run mplex: > > mplex -f 8 -L 48000:2:24 -o sample2448.mpg movie.m2v > sample2448.wav > >INFO: [mplex] mplex version 1.6.2 (2.2.3 $Date: > 2004/01/13 20:45:26 $) >INFO: [mplex] File black.m2v looks like an MPEG > Video stream. > **ERROR: [mplex] File unrecogniseable! > **ERROR: [mplex] Unrecogniseable file(s)... exiting. > are there problems with mplex and lpcm audio? if so, No, there are not any known problems if you give mplex a lpcm audio file. There are problems with a WAV files though. Strip off the WAV header and produce a 'raw' LPCM file and it will work. Granted, mplex probably _should_ see that it's a wav file and get the information it needs from that rather than the command line. 'sox' will produce "raw" output. > soundtrack for dvd movies can be a number of formats, > including lpcm in 16, 20 and 24 bits at 48 or 96 kHz. > is there a transformation that needs to happen on a > standard wav file to convert to lpcm first? my source Yes, something like sox input.wav sox.raw might do the trick - but check the manpage first ;) Most of the time folks are trying to squeeze as much playing time as possible onto a disc so uncompressed audio is not frequently used. 384Kb/s AC3 should be enough for all but the most 'golden ears' ;) Cheers, Steven Schultz --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
[Mjpeg-users] dvd with 24 bits/48 kHz audio
hello, i'm trying to create a dvd video with an lpcm soundtrack that has a sample size of 24 bits and a sample frequency of 48 kHz. when i run mplex: mplex -f 8 -L 48000:2:24 -o sample2448.mpg movie.m2v sample2448.wav i get this output: INFO: [mplex] mplex version 1.6.2 (2.2.3 $Date: 2004/01/13 20:45:26 $) INFO: [mplex] File black.m2v looks like an MPEG Video stream. **ERROR: [mplex] File unrecogniseable! **ERROR: [mplex] Unrecogniseable file(s)... exiting. are there problems with mplex and lpcm audio? if so, are they specific to certain sample sizes/rates? according to everything i've found so far, the soundtrack for dvd movies can be a number of formats, including lpcm in 16, 20 and 24 bits at 48 or 96 kHz. is there a transformation that needs to happen on a standard wav file to convert to lpcm first? my source wav file is verified to be good (it plays fine and multiple programs report 24 bits, 48 kHz). thanks for any input/feedback, chris __ Do you Yahoo!? Make Yahoo! your home page http://www.yahoo.com/r/hs --- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click ___ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
