PDA

View Full Version : DD AC3 5.1 always gets converted to DD AC3 2.0?



charlesml3
11-27-2005, 02:31 AM
Gang,

I've been beating my head against the wall all day on this one. Yes, I've read a TON of threads here, on DVD-Lab's forums and elsewhere. I just can't figure out if there's a way to do this. If anyone can get me going in the right direction, I'd sure be appreciative.

Anyway, I have a Radiohead concert saved on the HR10-250. When I play it, my processor (Lexicon MC-1) says the audio is Dolby Digital 5.1. It sounds that way as well. I used Tytools 9r18 to pull it down to the PC as a .TY file. I've tried a myriad of options to multiplex it, split it, etc. Every time it says:

Detected Tivo Type: HDTivo
Detected Audio Stream Type: Dolby Digital 5.1
Final standardAudioSize = 1552
Final standardFrameLength = 1536
Final standardAudioDiff = 2880 or 00:00:00.032
First Video PTS: 00:05:18.160
......... 100......... 200......... 300......... 400......... 500
......... 600......... 700......... 800......... 900......... 1000
......... 1100......... 1200......... 1300......... 1400......... 1500
......... 1600......... 1700......... 1800......... 1900......... 2000
......... 2100......... 2200......... 2300......... 2400......... 2500
......... 2600......... 2700......... 2800......... 2900......... 3000
......... 3100......... 3200......... 3300......... 3400......... 3500
......... 3600......... 3700......... 3800......... 3900......... 4000
......... 4100......... 4200......... 4300......... 4400......... 4500
......... 4600......... 4700......... 4800......... 4900......... 5000
......... 5100......... 5200......... 5300......... 5400......... 5500
......... 5600......... 5700......... 5800......... 5900......... 6000
......... 6100......... 6200......... 6300......... 6400......... 6500
......... 6600......... 6700......... 6800......... 6900......... 7000
......... 7100......... 7200......... 7300......... 7400......... 7500
......... 7600......... 7700......... 7800......... 7900......... 8000
......... 8100......... 8200......... 8300......... 8400......... 8500
......... 8600......... 8700......... 8800......... 8900......... 9000
......... 9100......... 9200......... 9300......... 9400......... 9500
.....

DiffTime = 130.909006 (130909) == 2.181817 Minutes

total = 1252917248 (1194 MB)

Done with 'D:\TyTivo\Radiohead.ty'...

A/V Sync Offset segment 1: -1ms (i.e. plays 1ms late!)

It looks like Tytools "sees" it as DD 5.1. However, if I pull the resulting file into DVD-Lab Studio, it says it's DD 2.0. Burning it down to a DVD and playing it in the home stereo confirms that (Lexicon says DD 2.0).

I've been tracking this back and it seems to be TyTools. If I choose the option File/Split Files, it generates a .m2a and .m2v file. I then examined the file with DelayCut and this is the output:

====== INPUT FILE INFO ========================
File is ac3
Bitrate (kbit/s) 384
Act rate (kbit/s) 384.000
File size (bytes) 224607744
Channels mode 2/0: L+R
Sampling Frec 48000
Low Frec Effects LFE: Not present
Duration 01:17:59.328
Frame length (ms) 32.000000
Frames/second 31.250000
Num of frames 146229
Bytes per Frame 1536.0000
Size % Framesize 0
CRC present: YES
=============================================
====== TARGET FILE INFO ======================
Start Frame 0
End Frame 146228
Num of Frames 146229
Duration 01:17:59.328
NotFixedDelay 0.0000
=============================================

-I've tried this with "Patch Audio Holes" on and off. No change.

-Audio Transcoding set to "None" or #8. None of the others seemed to make sense but there is no change.

-I pulled the resulting .m2a file into DVD-Lab Studio and it also says its DD 2.0.

A bunch of the threads I've read here suggest that this should work but I couldn't find one that specified the options I need or whatever it is I'm missing. Can someone here point me in the right direction?

Thanks a ton, everyone. This forum is astoundingly helpful!

-Charles

charlesml3
11-27-2005, 01:17 PM
OK,

I've been doing even more digging and I know what's happening. There are several minutes of "filler" before the concert starts in Dolby Digital 2.0. When the TyTool extraction starts, it picks that up and assumes the rest of the stream is DD 2.0 the whole way.

Now I need to use TyTools "Set Initial Jump" to skip over that part and start the extraction when the Dolby Digital 5.1 section starts. I played the original recording on the Tivo so I know it switches to DD 5.1 as soon as the opening credits appear. Now I need to figure out how to turn that time point into a chunk number.

I used audiocheck but the output really didn't tell me much (or I don't know how to read it.) I'm not going to paste the whole output from audiocheck here because it's HUGE. Here's the first part of it:

Processing 'Radiohead.ty':

checkNumRecs: Number of Records: 18165 (f5 46 7a bd)
Main Pump: Bad Chunk! Skipping!

checkNumRecs: Number of Records: 141 (8d 0 5f 80)
Dolby Audio segment starts at chunk #: 1

checkNumRecs: Number of Records: 35 (23 0 ff ff)
checkNumRecs: Number of Records: 38 (26 0 ff ff)
checkNumRecs: Number of Records: 43 (2b 0 ff ff)
checkNumRecs: Number of Records: 31 (1f 0 ff ff)
checkNumRecs: Number of Records: 29 (1d 0 ff ff)
checkNumRecs: Number of Records: 34 (22 0 11 80)
checkNumRecs: Number of Records: 32 (20 0 ff ff)
checkNumRecs: Number of Records: 35 (23 0 ff ff)
checkNumRecs: Number of Records: 44 (2c 0 ff ff)
checkNumRecs: Number of Records: 27 (1b 0 ff ff)

And the file continues on with a lot of this. Is there something here that will tell me which chunk starts the DD 5.1 stream?

Thanks again!

-Charles

charlesml3
11-28-2005, 08:43 AM
I worked with this some more last night and I've come to some conclusions that I hope someone here can confirm.

It looks as though the current version of AudioCheck cannot distinguish between a Dolby Digital 2.0 and a Dolby Digital 5.1 stream. The output from a run is in the previous message. The recording I have starts out in DD 2.0 and switches to 5.1 when the concert starts.

Anyone else worked with this kind of recording?

Thanks!

-Charles

Narf54321
11-28-2005, 10:54 AM
Since I don't know the internals of TyTool, this is more of a general answer. But, Dolby Digital is still a proprietary format (despite however they were able to get it jammed into the DVD spec) and regardless of the incoming stream, every amateur and pro-sumer tool I've used only outputs stereo (DD 2.0).

I'm not sure if it has more to do with licensing, or more that handling the main stereo feeds is much easier.

charlesml3
11-28-2005, 11:49 AM
Hi Narf,

Well, I did get it to work, but it was all trial and error. I knew the DD 5.1 stream started at 4:25 seconds into the recording. I just stated guessing at values for "Set Initial Jump" and finally found the right value. Once I plugged that in, the .MPG file was DD 5.1 the whole way. I was able to edit off the end of the video and then pull the video and audio into DVD-Lab Studio.

The process works, but it sure would be nice if TyTools could handle an audio stream switching during the conversion from .ty to .mpg.

Thanks!

-Charles