Hardware-based playback of audio encoded with AC3-Machine

[Lapin Malin]

I just begin in DVD encoding, I currently encode in SVCD,
I have a problem with the conversion of audio streams with AC3-Machine, My player (pioneer DVD-343) freezes with the re-encoded streams but doesn't freeze with the original streams,
I've used DVD-Maestro to author the DVD-RW and burned it with RecordNow Max.
My Settings : http://natdom98.free.fr/images/Forum/ac3m.png
Thanks.

[Lapin Malin]

Noboby to help me ?

[majerle]

if i understud you want to encode svcd with ac3 ????
Possible, but non standard

IIRC svcd want mpeg 2 sound.

bye bye

Andres

[II00I00I]

Yes, I have the same problem.
If I use an original ac3 file and do not transcode it, then author it with DVD Maestro I can play my DVD on my Pioneer DVD-525.
But when I transcode a mp3 or wav to ac3 using AC3Machine or BeSweet the DVD plays for a few seconds and then freezes. I can fast forward and then the movie again plays for a few seconds and freezes again.
I also tried the DVD that freezes on a PS2 and there the DVD plays but there is jerky video from time to time. I also plays on both my PC's with PowerDVD.
Could this have to do with the SPDIF?
What could be encoded different between an original ac3 and a transcoded ac3? VBR? CBR?
:( :(

[Lapin Malin]

Majerle : I've converted DVD to DVD-R (personnel copy) and this problem appears on converting AC3 to AC3 (448kbps to 384kbps),

II00I00I : I've just changed the bitrate in the AC3-Machine settings. I left all the other default settings.
I suppose BeSweet encodes in CBR.

[DSPguru]

i suggest you to send your comments to : ffmpeg-devel@lists.sourceforge.net (http://sourceforge.net/mailarchive/forum.php?thread_id=1558796&forum_id=1506)

[Lapin Malin]

OK, Thanks :)

[II00I00I]

OK, I posted all my remarks to the above email address.

But I got 1 step further also.
When I use Sonic Foundry SoftEncode to transcode the AC3 and use this file to author a DVD it plays fine on all devices (also the DV-525).
So now I use AC3Machine to transcode the AC3 to a new framerate.
Afterwards I transcode that AC3 with SoftEncode to have a correct playable file.

CYA,

II00I00I :) :) :)

[DSPguru]

great, i've noticed your letter.

you should know that this mailing list deals with the ffmpeg project, and ac3enc.dll that BeSweet/AC3Machine uses for ac3 encoding is taken from this project.
please, try focusing your letters to them about ac3enc. (most ffmpeg's mailing list members are not windows users, so i doubt they care/know about tmpgenc/powerdvd, etc'.. :D).


as for the usage of Soft-Encoder as AC3 encoder - that's a good solution, but you shouldn't encode to ac3 twice (BeSweet+SoftEncoder). you better create a 6ch wave with BeSweet, and then encode it to ac3 with soft-encoder.

[delly01]

Hello,

I have just experienced the same problem when I transcoded a DVD in PAL. The sound was AC3-448 KHz 5.1, and I reduced it to 192 and 224 KHz 2.0, and tried a lot of different settings for azid and besweet. The resulting DVDs would play fine on my PC with PowerDVD 4.0, but they would freeze on my Pioneer DV-323 after about 2s. There was a buzzing sound after about a second, and a second later the picture froze.

The problem was smaller when I switched the output to "stereo" instead of "surround2", but the screech/freeze happened within the first chapter. Skipping to the next, I could view some minutes and had it happen again.

I tried a lot of variants in Besweet Gui and ac3machine, the letter one is making life a lot easier by eliminating a lot of options ;-)

As I live in Europe, I could work around the problem by producing MP2 which is a correct option for R2-DVDs, but I would like to use AC3 as well.

Bye,

Detlev Rackow

[henry_nettles]

The following was taken from the usenet news group rec.video.desktop

>>>You can find a free encoder on-line, called AC3Encode, that works with
>>>the BeSweet encoder (Google for it). The problem, apparently, is that
>>>it only encodes in Intel byte order. So your DVDs might play on a PC,
>>>but wouldn't play on most set-top players.
>>
>> Is that really true? Havn't read that anywhere else. I just burned a DVD
>>yesterday and it played on my old Toshiba DVD player without a hitch. This
>>thing won't even play a VCD or SVCD at all...
>
>It _was_ true. I haven't looked at AC3Encode in quite awhile, maybe
>they've fixed it.
>
>In theory, every AC3 player is supposed to play both byte-order
>encodings, at least according to the Dolby Labs blurb I read when I
>first found this not working. As it turned out, my Pioneer didn't
>play, some of the AC3 manipulation tools I had lurking around didn't
>accept the format, etc. That doesn't mean that other DVD players won't
>play it, even if the problem still exists. It also doesn't mean the
>problem still exists. I suspect it's mentioned in the maintainence
>notes for AC3encode (or the ac3enc.dll they're using).
>
>If it's actually fixed, I'd like to know, just so I stop telling
>people to beware of this.
>

It is not fixed, I have the problem with my Pioneer settop player.

[DSPguru]

can someone confirm this info by encoding an ac3 track with BeSweet/AC3Enc, flipping byte-order in this file and authoring a dvd ?

[delly01]

Originally posted by DSPguru
can someone confirm this info by encoding an ac3 track with BeSweet/AC3Enc, flipping byte-order in this file and authoring a dvd ?

I'm really willing to do this if you explain to me how to change the byteorder. However, I do not believe that the problem is caused by the byteorder, as my pioneer will make the screeching noise after about half a second, not right at the beginning.

Have I missed a switch in the docs, or do I need an additinal tool to change the byteorder?

Bye,

Detlev

[henry_nettles]

I just performed a very simple byte swap ("ab" becomes "ba"), and it did not fix the problem. I suspect there may be more to this (possible headers in the file?).

Here is the 'c' source code that I used:

#include <dos.h>
#include <stdio.h>
#include <stdlib.h>


void main(int argc, char *argv[])
{
unsigned short w1,w2;
FILE* in;
FILE* out;

if (argc != 3) {
printf("\n Error: usage is:");
printf("\n byte1 input.file output.file \n");
exit(0);
}

in = fopen(argv[1],"rb");
if (in == NULL) {
printf("\n failed to open input file %s \n",argv[1]);
exit(0);
}

out = fopen(argv[2],"wb");
if (out == NULL) {
printf("\n failed to open output file %s \n",argv[2]);
exit(0);
}

while (fread(&w1,sizeof(w1),1,in)) {
swab((unsigned char *)&w1,(unsigned char *)&w2, 2);
fwrite(&w2,sizeof(w2),1,out);
}
}

[Mago]

It seems as besweet and pioneer dont work so great together. I also had the same problem on my Pioneer NSDV55. Switching to Soft Encoder fixed the problem.

I checked litle about the byte order and found the following:
Besweet AC3 are in Motorola byte order. If you take an AC3 file from Besweet and load it into Soft Encoder and run Verify File it says File OK, Byte order: non-Intel.

The problem was very strange on my Pioneer. I could see 53 seconds of the film, then it froze. After that I could fastforward and mayby see 1 or 2 seconds befor it froze again. The film was Signs and an interesting thing was that after 53 seconds the sound should be much louder. It was then it froze. Mayby the problem lies in the conversion from samples into floating point?!??

[DSPguru]

1. i doubt byte-flipping will make a difference.
2. please mention if you encoded a 2.0ch stream or 5.1ch.
3. floating-point got nothing to do with it :)

[delly01]

Afair, I tried to convert 5.1 to 2.0.

Bye,

Detlev

[shindig]

I had this problem also but I´ve found a way to get through:
Take the original WAV to BeSweet and make 6 WAVs. Then take these 6 WAVs to SoftEncode and make the AC3. It works for me every time and plays fine on my Pioneer.
This has been up earlier in this thread by DSPguru.
/Shindig

[feeky1973]

my problem is this:
i am taking avi's(divx/xvid) and converting them into dvd.
after trying several different methods i found the best to be dvd2svcd-spruceup-recordnow.

this works great for non ac3 files but when i do the process with an ac3 file playback on my pioneer freezes constantly.

i have tryed different combinations of dvd-r, authoring and burning software and looking at different threads have realised it is a problem with besweet and pioneer(something about being non-intel).
does anyone no a way round this problem? there must be a simple fix.

[lpn1160]

Just wondering if anyone else has noticed the same problem.
Ran some tests, and using besweet encoding to.ac3 from .wav extracted from analogue caps the only bitrate that plays on my standalone, without stutter (aiwa dv-380)is 224kbps. using softencode ALL bitrates played without stutter. Tested bitrates from 128kbps upto 448kbps. Test methods using both Motorola and Intel byte order.
I love using Besweet because it is so fast compared to softencode.
Video format was huffyuv capped source frameserved with avisynth to CCE VBR 2500-8000 mpeg2 (720x480)
Anyone know the whys for this problem ??

[KpeX]

I have been experimenting with encoding six wave's --> ac3 with BeSweet, via the method described here (http://forum.doom9.org/showthread.php?s=&threadid=49118) and here (http://forum.doom9.org/showthread.php?s=&threadid=55610).

However, I have found that the resulting .ac3 file will not play when AC3Filter 0.68b is set to S/PDIF output. File plays back fine when set to any other speaker configuration, such as 2 channel, but will not play or render in GraphEdit when set to S/PDIF. Other AC3 files such as those demuxed from a DVD play back fine via S/PDIF. I also tried muxing into a .mka, which didn't help either. Any suggestions or input would be appreciated.

[S_O]

Some questions:
-Does your decoder/receiver play nothing or noise?
-Does the decoder/receiver detect Dolby-Digital (is the lamp on)?

Does your file have the same samplerate like other DVDs-AC3s (48kHz)? Because of limitations in my soundcard I can only playback 48kHz AC3 through S/PDIF.

[KpeX]

Yep, resampled to 48 Khz and it plays back fine. Can't believe I missed that obvious difference between the AC3 files earlier. With AC3 files at 44.1 Khz it would not play at all - i.e. the DirectShow player would act as if there was not a proper filter/codec installed. Anyways playback is all good now, thanks very much for the reply, S_O :D.