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Old 18th October 2005, 11:42   #1  |  Link
gumballguy
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Need specification for this strange AC3 stream

Hi

My fusionhdtv card allows to save to mpeg instead of ts. When I first got the card, I thought this was a safer option, so I always recorded to mpeg. However, I cannot demux and cut streams when editing/encoding. Can anyone demux this sample file?

So far I have tried:
Projectx
PVAStrumento
TMPEG
simply cutting without demuxing using mpeg2schnitt then attempting to work with the output. Obviously, bad.

There is a sample clip at http://www.arach.net.au/~watto/2005-06-06.zip

Additionally, I fear that without using a program such as projectx, I'm going to end up with sync issues. Still, first step is to actually demux this thing!

Last edited by Guest; 18th October 2005 at 17:20.
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Old 18th October 2005, 15:03   #2  |  Link
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I can demux the video with no problem using DGIndex 1.4.6b1. But the stream does not contain any audio, so there is no demuxed audio stream. At least there's no need to worry about sync.
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Old 18th October 2005, 15:48   #3  |  Link
gumballguy
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Ah, there IS audio though! Play it in mpc (or wmp 6.4)!

I downloaded my own file and investigated to make sure I hadnt uploaded the wrong thing... and thats the correct file. Notably, it WONT play audio in VLC, which I only just discovered.

Im not sure if the PID's stay constant across filetypes (I suspect they dont), but a recording from the same tv channel to .ts format gives this:
Video: PID: 0x20A
Audio: PID: 0x2EE(AC-3)(eng)_PD
The ac3 stream will be 48000/384.

Last edited by gumballguy; 18th October 2005 at 15:52.
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Old 18th October 2005, 16:21   #4  |  Link
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Hmm, interesting. I'll trace through it with the debugger and find out why DGIndex isn't seeing the audio. I'm home sick today.
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Old 18th October 2005, 17:20   #5  |  Link
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It's not standard AC3, so I can't help with this without further information. It appears on private stream 1 as it should, but the audio substream ID is 0x0b, when it should be 0x80-0x87. And then the rate has a reserved value. I stopped looking after that. Patching the ID to 0x80 did not work.

I would consider supporting it if you can point to a spec that describes it.

Moving to the Audio forum and changing title.

Last edited by Guest; 18th October 2005 at 17:24.
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Old 18th October 2005, 18:22   #6  |  Link
guada 2
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Hello gumballguy,

Sorry, PVASTRUMENTO perfectly functions;
Look at the result:

PVAStrumento 2.1.0.12
*** running at 10-18-2005 19:10
***
Pre-Scanning input. Takes some time.
Stream info for
C:\Documents and Settings\desbonne\Mes documents\log récent\Nouveau dossier\2005-06-06.mpg

Found 1 video stream.
Found 1 AC3 audio stream.

VIDEO #1
Resolution 1440 x 1088
Aspect ratio is 16:9
Frame rate 25.00 fps
Nominal bitrate 12800000 bps
First PTS: 00:00:00.724

AC3 AUDIO #1
Format: 2/0
Sampled at 48.0 kHz.
First PTS: 00:00:00.112


<<DEMUXING>>
Input: C:\Documents and Settings\desbonne\Mes documents\log récent\Nouveau dossier\2005-06-06.mpg
Options
.. fixing stream synch.
.. keeping track of audio offset accumulation.
.. strict checking of audio framing.
.. dropping GOPs longer than 980 KB
.. splitting on change of video format.
.. splitting on change of audio format.
.. splitting on number of audio tracks.
.. clearing CDF
.. creating new GOP timecodes.

Closing starting GOP.
Aiming for sync at 00:00:00.804
Cutting audio.
AC3 stream 1 now starts at 00:00:00.816
Video stream 1 now starts at 00:00:00.804
New MPEG video : \2005-06-06.mpv
New AC3 audio : \2005-06-06.ac3
****FileSpan for PES packet
Adjusting audio to frames in last GOP at EOF
Last fileset:
8494381 total bytes written
Video 1: 130 frames, 00:00:05.200
AC3 1: 150 frames, 00:00:04.800

Video statistics
================
GOP length (min/avg/max):
10 / 11 / 12 [frames]
690317 / 758101 / 767837 [Bytes]
GOP bitrate (min/avg/max):
12304 / 12844 / 13806 [kbps]


(Autosaving log to \2005-06-06.txt)

Bye.
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Old 18th October 2005, 19:00   #7  |  Link
gumballguy
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Neuron2, im not so sure that its the ac3 stream as to how its placed into the file. I doubt that my hd card alters the stream according to whether it saves it into an mpeg or ts.

guada2, I shall have another attempt at it soon. From memory, the problem with pvastrumento is that it stops part of the way through a large file for an unknown reason. Let me verify that statement first though, and make sure I was running the newest PVAs at the time.

Replies may be delayed, I am under extreme pressure to finish writing my thesis! Hopefully I will find a few minutes spare tomorrow... its 2am atm, so g'night.
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Old 18th October 2005, 20:23   #8  |  Link
guada 2
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gumballguy,

* What is the exact reference of your card?

* I wondered if Dvico' S was compatible with the mode of recognition of DGindex. Because one not to forget that it has his own AC3, AAC, MP2 and MP1 audio decoder.......
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Old 18th October 2005, 22:35   #9  |  Link
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Apparently it's related to the difference between Australian and ATSC standards. I could try to reverse engineer PVAStrumento, but it would be easier if someone gave me the spec.

Do you have the Australian format card or the ATSC format card?
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Old 19th October 2005, 04:36   #10  |  Link
setarip_old
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@gumballguy

Hi!

Quote:
Can anyone demux this sample file?

So far I have tried:
Projectx
PVAStrumento
TMPEG
I was able to demultiplex your 5 second clip using good ol' reliable TMPGEnc v.1.2 (I'm fairly certain all more current versions would work as well), as follows:

TMPGEnc>>File>>MPEGTools>>Demultiplex (NOT "Simple Demultiplex")

I doubleclicked on the "private_stream_1 (0x0B)" and saved it with an .AC3 extender
I then doubleclicked on the "video_stream 0x00" and saved it with an .M2V extender

Each individual stream played normally under Windows Media Player...
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Old 19th October 2005, 17:54   #11  |  Link
gumballguy
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Aha.. private stream. Id not thought of saving that as an ac3 file, I had imagined it to be a teletext file or something.

Neuron2, I will find you that info if possible in the near future. Will check product manual and then email the makers of the card. I shall pm you, so no need to check the thread.

Please note that this will be my last reply for a while (could be a couple weeks), I woke up to find my hdd failing miserably. My first priority is to recover that data before any more forum use
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Old 19th October 2005, 19:35   #12  |  Link
guada 2
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gumballguy,

I have an idea on the choice of your card. I understand your discretion....

However, if you want to find your data, uses this software: EASYRECOVERY PROFESSIONAL.

Bye.
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Old 19th October 2005, 20:16   #13  |  Link
guada 2
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With ADCTools I found this:

bitRate = 1536000
samplerate = 48000
channels = 2
bitPerSample = 16


MPC

Video: MPEG2 Video 1440x1088 (16:9) 25.00fps 12800Kbps
Audio: Dolby AC3 48000Hz stereo 256Kbps
Video: äS


Where is the truth?
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Old 19th October 2005, 20:26   #14  |  Link
eb
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not for every case but for most cases bbtool1.9 is very useful

bbINFO - version 1.9, by Brent Beyeler (beyeler@home.com)
speed increases by, Apachez and Christian Vogelgsang

File 1 is an MPEG-2 Program Stream


PACK #0, pack_start_code = 000001BA, SCR = 112.280778 ms
stream_id = BD Private Stream 1, packet #0, PTS = 112.277778 ms, underflow

PACK #1, pack_start_code = 000001BA, SCR = 112.280778 ms
stream_id = BD Private Stream 1, packet #1,

PACK #2, pack_start_code = 000001BA, SCR = 112.280778 ms
stream_id = BD Private Stream 1, packet #2,

PACK #3, pack_start_code = 000001BA, SCR = 112.280778 ms
stream_id = E0 Video Stream 0, packet #0, PTS = 804.644444 ms, DTS = 684.644444 ms
0 - sequence_header_code
140 - extension_start_code
150 - user_data_start_code
161 - group_of_pictures header
169 - picture_start_code
178 - extension_start_code

PACK #4, pack_start_code = 000001BA, SCR = 112.280778 ms
stream_id = E0 Video Stream 0, packet #1,

Summary:

MPEG Packs = 1263
Private Stream 1 packets = 176, total bytes = 180224
Video stream 0 packets = 1087, total bytes = 8882053
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Old 19th October 2005, 20:36   #15  |  Link
guada 2
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Hello eb,

For the video it is not a problem.
And for the audio?

What utilitarian other that you know?
Perhaps Mr question man ?????
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Old 19th October 2005, 20:43   #16  |  Link
eb
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use bbdmux 1 0xBD 1.ac3
where 1 is above file renamed

EDIT:
and to demux video use
bbdmux 1 0xE0 1.m2v

Last edited by eb; 19th October 2005 at 20:48.
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Old 21st October 2005, 17:34   #17  |  Link
calinb
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Quote:
Originally Posted by gumballguy
Hi

My fusionhdtv card allows to save to mpeg instead of tp. When I first got the card, I thought this was a safer option, so I always recorded to mpeg. However, I cannot demux and cut streams when editing/encoding. Can anyone demux this sample file?
gumballguy,

I've had the same problem with mpeg files created by my ATSC Fusion card. I suggest using .tp (Fusion transport stream), if you can. I've been demuxing / recoding the .tp files for a couple of years, with, generally, no sync problems. On the rare occasion that I have a sync problem, I use MPC to determine the delay required and remux with avimuxGUI or mkvmerge/mmg.

Unfortunately for me, I must use mpeg on one QAM channel only. If I use .tp output, the stream is corrupted. I'm working this issue with Dvico customer support.

I've had good luck demuxing the mpeg files with the Windows mpeg demultiplexer DSF (not the Windows mpeg "splitter"). See my previous post. Although it's possible, with the right set of DSFs, to save the audio to .ac3, I just save to a .wav file and use besplit to "fix" the ac3 wav file to a .ac3 file afterwards. If you have trouble, I'll try to find time to post my graphedit filter graph for you.
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Old 20th May 2006, 19:14   #18  |  Link
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I finally figured this out!

Private stream 1 carries the AC3. But the way it is packed in there is different for DVD and non-DVD streams. For DVD streams, there is an audio substream number and an associated DVD-specific header. For plain vanilla MPEG, there is no audio substream number and header. I revised DGIndex to detect the difference and handle it. I tested it on one Fusion card capture and it worked. Please test this on your Fusion MPG streams and notify me if anything doesn't work. Thank you.

BTW, the 0x0b, which I was trying to interpret as the substream id, was actually the first byte of the AC3 sync word!

Of course, because DVD2AVI was designed for DVD streams, it didn't know or care about this. And because DGIndex was derived from DVD2AVI...

http://neuron2.net/dgmpgdec/dgmpgdec147b12.zip

Last edited by Guest; 27th May 2006 at 06:15.
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Old 27th May 2006, 02:18   #19  |  Link
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Thanks, Donald! Initial testing with a Fusion .mpg file indicates the new feature is working. However, I ran into a problem with Fusion .tp files that must've crept in somewhere; preview is not currently working on .tp files, though I can move the cursor along the timeline okay. Upon hitting F5, the information window opens but it contains no information and DGIndex freezes. It demuxes and makes project files though.

Let me know if you need any sample clips and , as always!
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Old 27th May 2006, 06:11   #20  |  Link
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Maybe you left the playback speed set to single-step. But if not...

Which version?

If it does that with 1.4.7b12, please upload a stream to my FTP. I'll PM you the password. Good timing, I was just about to release 1.4.7.

Thank you for pointing it out.

Last edited by Guest; 27th May 2006 at 06:17.
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