Besweet: Crackling sound mp2 -> ac3

[MrWGT]

Hi...

i own a dvd player which has bugs with mp2 sound. So i want to convert my mpg videos (with mp2 384kBit) into mpg videos with 256 kBit ac3 2.0 sound.

I use TMPGENC to demux the mpg into m2v and mp2. To convert the mp2 into a ac3 i use the following command line (in a batch file):

BeSweet.exe -core( -input %1 -output %1.ac3 -substream SubS ) -ac3enc( -b 256 )

%1 is the filename e.g. "DragonBallZ-2002-12-12.mp2". The resulting file is "DragonBallZ-2002-12-12.mp2.ac3"

If i listen to the ac3 with e.g. PowerDVD i hear many crackling sound in voices. (no crackling recognized during background music).

BUT: If i convert the mp2 into wav and the wav into ac3 NO crackling is there. Playback in PowerDVD is OK!!!

command line for mp2->wav->ac3:

BeSweet.exe -core( -input %1 -output %1.wav -2ch ) -ssrc( --normalize )
BeSweet.exe -core( -input %1.wav -output %1.ac3 -substream SubS ) -ac3enc( -b 256 )

Can anybody explain this behavior of besweet?

Regards,

Gerd Mitländer

PS: I've tried to use the -ssrc( --normalize ) with the first command line but the resulting ac3 was still crackling.

[DSPguru]

How to submit bugreports (http://forum.doom9.org/showthread.php?s=&threadid=15738)
sound cracklings with BeSweet (http://forum.doom9.org/showthread.php?s=&threadid=39609)

[MrWGT]

Thanks for the reply...

Unfortunatly i can't find a solution following the links. (Or perhaps i'm to stupid to find it)

1) i'm not doing a framerate conversion. (no pal2ntsc)
2) i'm not doing a time stretching.
3) i'm not doing a sample rate conversion. (no 44k1 to 48k)

I've used BeSweet 1.4 and the latest available beta version from doom9.

My mp2 is 48k 2.0 and my ac3 should be 48k 2.0 too.

I thought that BeSweet is (mp2->ac3)

1) Read the mp2
2) convert into pcm samples
3) creates ac3 using ac3enc.dll

In case of (mp2->wav and after that wav->ac3)

1) Read the mp2
2) convert into pcm samples
3) writes pcm samples into wave file

4) Read pcm samples from wav
5) creates ac3 using ac3enc.dll

The difference should only the above steps 3/4. But the ac3 files are different (first is garbage and second is ok).

Gerd

[DSPguru]

this bugreport is very interesting, and i would like to fix this issue, if exist.
but i need your help with supplying more info.
Originally posted by DSPguru
1 a. make sure you're using the latest release of BeSweet. (i can't support old versions).
4 d. please state the command line was used. (if you use the GUI - click the "Copy command to clipboard" button).
5 e. always create a logfile and paste it in your thread. the whole logfile ! (let me decide what is relevant, and what isn't)
7 g. if it could be relevant - point out the operating system/computer system was used.

[MrWGT]

Hi...

i'm currently trying to reproduce the effect with logfile enabled. I had used BeSweet 1.4 and 1.5b8 and now i'm using 1.5b9.

Up to now i had no "success" (or all conversions are ok).

Could i be that this problem is related to multiple ac3 conversions running at the same time? As written in my first mail i'm currently converting my mpgs with mp2 audio into m2v and mp2 with bbdmux. The demuxed mp2 audio is converted with BeSweet to ac3.

I've written a batch file for the demux and conversion process. Before going to bed i do a drag&drop of e.g. 30 files (one file per drag&drop) onto the batch file (located on desktop). During the night the mpgs are demuxed and converted.

My (initial) batchfile was:

@ECHO OFF
SET BITRATE=256
ECHO Umwandlung MPEG2-Video/Audio nach M2V und AC3 %BITRATE% kBit...
if exist %1.m2v GOTO AUDIO
ECHO Demuxe Videostream aus %1 nach %1.m2v
bbdmux %1 0xE0 %1.m2v
:AUDIO
if exist %1.mp2 GOTO AC3
ECHO Demuxe Audiostream aus %1 nach %1.mp2
bbdmux %1 0xC0 %1.mp2
:AC3
if exist %1.ac3 GOTO FINISHED
ECHO Generiere AC3 %1.%BITRATE%.ac3 aus %1.mp2
BeSweet.exe -core( -input %1.mp2 -output %1.%BITRATE%.ac3 -substream SubS ) -ssrc( --normalize ) -ota( -d 0 ) -ac3enc( -b %BITRATE% )
:FINISHED
ECHO Beendet...
pause

My current batch file is:

@ECHO OFF
SET BITRATE=256
ECHO Umwandlung MPEG2-Video/Audio nach M2V und AC3 %BITRATE% kBit...
if exist %1.m2v GOTO AUDIO
ECHO Demuxe Videostream aus %1 nach %1.m2v
bbdmux %1 0xE0 %1.m2v
:AUDIO
if exist %1.mp2 GOTO WAV
ECHO Demuxe Audiostream aus %1 nach %1.mp2
bbdmux %1 0xC0 %1.mp2
:WAV
if exist %1.wav GOTO AC3
ECHO Generiere Wave %1.wav aus %1.mp2
BeSweet.exe -core( -input %1.mp2 -output %1.wav -logfilea %1.mp2.log -2ch ) -ssrc( --normalize )
:AC3
if exist %1.ac3 GOTO FINISHED
ECHO Generiere AC3 %1.%BITRATE%.ac3 aus %1.wav
BeSweet.exe -core( -input %1.wav -output %1.%BITRATE%.ac3 -logfilea %1.ac3.log -substream SubS ) -ota( -d 0 ) -ac3enc( -b %BITRATE% )
:FINISHED
ECHO Beendet...
pause

Gerd

[DSPguru]

i don't understand why do you use bbdmux, instead of letting BeSweet to directly process the .vob input.

anyway, if you have any issue, post logfiles.

[Herg]

Sorry to resurrect this thread, but I have run into the same problem, and I have logs!

*************************************************************
Pass 1 - mp2->ac3 Clicking present
*************************************************************

BeSweet v1.5b18 by DSPguru.
--------------------------
Using hip.dll v1.19 by Myers Carpenter <myers@users.sf.net>
Using Shibatch.dll v0.24 by Naoki Shibata & DSPguru (shibatch.sourceforge.net).
Using AC3enc.dll v0.21 by Fabrice Bellard (http://ffmpeg.org).

Logging start : 05/29/03 , 15:35:18.

BeSweet -core( -input input.mp2 -output output.ac3 -logfile log1.txt ) -ssrc( --rate 48000 ) -ac3enc( -b 224 )

[00:00:00:000] +------- BeSweet -----
[00:00:00:000] | Input : input.mp2
[00:00:00:000] | Output: output.ac3
[00:00:00:000] | Floating-Point Process: No
[00:00:00:000] +------ Shibatch -----
[00:00:00:000] | Source Sample-Rate: 44.1KHz
[00:00:00:000] | Dest. Sample-Rate: 48.0KHz
[00:00:00:000] | Attenuation : 0.0db
[00:00:00:000] +------- AC3ENC ------
[00:00:00:000] | Bitrate method : CBR
[00:00:00:000] | AC3 bitrate : 224
[00:00:00:000] | Channels Mode : 2.0
[00:00:00:000] | Error Protection: Yes
[00:00:00:000] +---------------------
[00:03:01:865] Conversion Completed !
[00:03:01:865] Actual Avg. Bitrate : 111kbps
[00:00:07:000] <-- Transcoding Duration

Logging ends : 05/29/03 , 15:35:25.

*************************************************************
Pass 2 - mp2->wav->ac3 Clicking not present
*************************************************************

BeSweet v1.5b18 by DSPguru.
--------------------------
Using hip.dll v1.19 by Myers Carpenter <myers@users.sf.net>
Using Shibatch.dll v0.24 by Naoki Shibata & DSPguru (shibatch.sourceforge.net).

Logging start : 05/29/03 , 15:36:27.

BeSweet -core( -input input.mp2 -output output.wav -logfile log2.txt -2ch ) -ssrc( --rate 48000 )

[00:00:00:000] +------- BeSweet -----
[00:00:00:000] | Input : input.mp2
[00:00:00:000] | Output: output.wav
[00:00:00:000] | Floating-Point Process: No
[00:00:00:000] +------ Shibatch -----
[00:00:00:000] | Source Sample-Rate: 44.1KHz
[00:00:00:000] | Dest. Sample-Rate: 48.0KHz
[00:00:00:000] | Attenuation : 0.0db
[00:00:00:000] +---------------------
[00:03:01:865] Conversion Completed !
[00:03:01:865] Actual Avg. Bitrate : 767kbps
[00:00:05:000] <-- Transcoding Duration

Logging ends : 05/29/03 , 15:36:32.


BeSweet v1.5b18 by DSPguru.
--------------------------
Using AC3enc.dll v0.21 by Fabrice Bellard (http://ffmpeg.org).

Logging start : 05/29/03 , 15:37:33.

BeSweet -core( -input output.wav -output output2.ac3 -logfile log3.txt ) -ac3enc( -b 224 )

[00:00:00:000] +------- BeSweet -----
[00:00:00:000] | Input : output.wav
[00:00:00:000] | Output: output2.ac3
[00:00:00:000] | Floating-Point Process: No
[00:00:00:000] | Source Sample-Rate: 48.0KHz
[00:00:00:000] +------- AC3ENC ------
[00:00:00:000] | Bitrate method : CBR
[00:00:00:000] | AC3 bitrate : 224
[00:00:00:000] | Channels Mode : 2.0
[00:00:00:000] | Error Protection: Yes
[00:00:00:000] +---------------------
[00:01:30:880] Conversion Completed !
[00:01:30:880] Actual Avg. Bitrate : 224kbps
[00:00:03:000] <-- Transcoding Duration

Logging ends : 05/29/03 , 15:37:36.

*************************************************************
Pass 3 - mp2->ac3 (without -ssrc) Clicking present
*************************************************************

BeSweet v1.5b18 by DSPguru.
--------------------------
Using hip.dll v1.19 by Myers Carpenter <myers@users.sf.net>
Using AC3enc.dll v0.21 by Fabrice Bellard (http://ffmpeg.org).

Logging start : 05/29/03 , 15:38:05.

BeSweet -core( -input input.mp2 -output output4.ac3 -logfile log4.txt ) -ac3enc( -b 224 )

[00:00:00:000] +------- BeSweet -----
[00:00:00:000] | Input : input.mp2
[00:00:00:000] | Output: output4.ac3
[00:00:00:000] | Floating-Point Process: No
[00:00:00:000] | Source Sample-Rate: 44.1KHz
[00:00:00:000] +------- AC3ENC ------
[00:00:00:000] | Bitrate method : CBR
[00:00:00:000] | AC3 bitrate : 224
[00:00:00:000] | Channels Mode : 2.0
[00:00:00:000] | Error Protection: Yes
[00:00:00:000] +---------------------
[00:03:01:830] Conversion Completed !
[00:03:01:830] Actual Avg. Bitrate : 111kbps
[00:00:04:000] <-- Transcoding Duration

Logging ends : 05/29/03 , 15:38:09.