Thread: MPEG-2 Capture?
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From: Aleksandr M. <n6...@mi...> - 2001-02-05 23:41:52
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Has anyone done any work on MPEG-2 capture from 1394? I'm looking for a simple, dumb, strip off the 1394 headers and write the MPEG-2 packets to disk kind of utility. The application is capturing MPEG-2 broadcasts that have been recorded with a D-VHS deck. Once I get the MPEG-2 captured, I can drag it into the NLE of my choice. Unfortunately, these devices (Panasonic PV-HD1000, Hughes Platinum set-tops and HDR-205 D-VHS deck, &c) implement what I've heard called "Brain Dead 1394" My understanding is that they simply spew isochronous 1394 packets that encapsulate MPEG-2 TS 188-byte packets. No device control, etc. I admit that I haven't built linux1394 yet, so if this is as simple as cat /dev/video1394 >> file.mpeg feel free to point that out. Thanks in advance, -Zandr -- --------------------------------------------------------------------- Aleksandr Milewski N6MOD n6...@mi... http://www.milewski.org/ |
From: Dan D. <dde...@co...> - 2001-02-06 05:52:50
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Aleksandr Milewski wrote: > > Has anyone done any work on MPEG-2 capture from 1394? Not that we are aware of. Most us are capturing DV and uncompressed video. > > I'm looking for a simple, dumb, strip off the 1394 headers and write > the MPEG-2 packets to disk kind of utility. > > The application is capturing MPEG-2 broadcasts that have been > recorded with a D-VHS deck. Once I get the MPEG-2 captured, I can > drag it into the NLE of my choice. > > Unfortunately, these devices (Panasonic PV-HD1000, Hughes Platinum > set-tops and HDR-205 D-VHS deck, &c) implement what I've heard called > "Brain Dead 1394" My understanding is that they simply spew > isochronous 1394 packets that encapsulate MPEG-2 TS 188-byte packets. > No device control, etc. > > I admit that I haven't built linux1394 yet, so if this is as simple as > > cat /dev/video1394 >> file.mpeg Not that simple until someone brings video1394 up to video4linux compliancy. However, you can certainly call a few ioctls and dump the iso packets to disk. If it is that braindead, then maybe it will be as simple as that, but I would not be so optimistic. > feel free to point that out. > > Thanks in advance, > -Zandr > -- > --------------------------------------------------------------------- > Aleksandr Milewski N6MOD > n6...@mi... http://www.milewski.org/ > > _______________________________________________ > mailing list Lin...@li... > http://lists.sourceforge.net/lists/listinfo/linux1394-user |
From: Dan D. <dde...@co...> - 2001-02-06 06:08:06
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Dan Dennedy wrote: > > Aleksandr Milewski wrote: > > > I admit that I haven't built linux1394 yet, so if this is as simple as > > > > cat /dev/video1394 >> file.mpeg > > Not that simple until someone brings video1394 up to video4linux > compliancy. However, you can certainly call a few ioctls and dump the > iso packets to disk. If it is that braindead, then maybe it will be as > simple as that, but I would not be so optimistic. Also, you could just use libraw's iso read functions. It is more universal, popular and simple. You can view the source of dvgrab to see how to use it. Access dvgrab at http://www.schirmacher.de/arne/dvgrab/. +-DRD-+ |
From: Aleksandr M. <n6...@mi...> - 2001-02-06 08:25:22
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At 1:03 AM -0500 on 2/6/01, Dan Dennedy commanded the electrons to create a missive titled "Re: MPEG-2 Capture?": |Aleksandr Milewski wrote: |> |> Has anyone done any work on MPEG-2 capture from 1394? | |Not that we are aware of. Most us are capturing DV and uncompressed |video. Uncompressed? From what source? |> I admit that I haven't built linux1394 yet, so if this is as simple as |> |> cat /dev/video1394 >> file.mpeg | |Not that simple until someone brings video1394 up to video4linux |compliancy. However, you can certainly call a few ioctls and dump the |iso packets to disk. If it is that braindead, then maybe it will be as |simple as that, but I would not be so optimistic. I'm reasonably sure it is that braindead. According to one source, each iso packet contains either one or two 188-byte Mpeg2 TS packets, "with header and timestamp." Sounds braindead to me. In any case... At 1:18 AM -0500 2/6/01, Dan Dennedy wrote: |Also, you could just use libraw's iso read functions. It is more |universal, popular and simple. You can view the source of dvgrab to see |how to use it. Access dvgrab at http://www.schirmacher.de/arne/dvgrab/. This is the right thing to do. I'll look at the source, but I have a suspicion that commenting out large pieces of dvgrap might be the way to go. Of course, the reason I asked this on the user list is that I'm far more user than developer, so if someone would like to lead the way... -Zandr -- --------------------------------------------------------------------- Aleksandr Milewski N6MOD n6...@mi... http://www.milewski.org/ |
From: Dan D. <dde...@co...> - 2001-02-06 17:49:15
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From: "Aleksandr Milewski" <n6...@mi...> > At 1:03 AM -0500 on 2/6/01, Dan Dennedy commanded the electrons to > create a missive titled "Re: MPEG-2 Capture?": > |Aleksandr Milewski wrote: > |> > |> Has anyone done any work on MPEG-2 capture from 1394? > | > |Not that we are aware of. Most us are capturing DV and uncompressed > |video. > > Uncompressed? From what source? Mostly closed circuit CCD-type Sony cameras for machine vision and industrial applications. However, several people have the Orange Micro iBot or Pyro WebCam cheap desktop cameras. > |> I admit that I haven't built linux1394 yet, so if this is as simple as > |> > |> cat /dev/video1394 >> file.mpeg > | > |Not that simple until someone brings video1394 up to video4linux > |compliancy. However, you can certainly call a few ioctls and dump the > |iso packets to disk. If it is that braindead, then maybe it will be as > |simple as that, but I would not be so optimistic. > > I'm reasonably sure it is that braindead. According to one source, > each iso packet contains either one or two 188-byte Mpeg2 TS packets, > "with header and timestamp." Sounds braindead to me. Well, then I strongly recommend the libraw API's functions as video1394 is rather tricky when dealing with variable-size packets because packets will split across the boundaries of the buffers. > In any case... > > At 1:18 AM -0500 2/6/01, Dan Dennedy wrote: > |Also, you could just use libraw's iso read functions. It is more > |universal, popular and simple. You can view the source of dvgrab to see > |how to use it. Access dvgrab at http://www.schirmacher.de/arne/dvgrab/. > > This is the right thing to do. I'll look at the source, but I have a > suspicion that commenting out large pieces of dvgrap might be the way > to go. There is a test mode of dvgrab and corresponding function that you should look at for the case that is closest to yours. > Of course, the reason I asked this on the user list is that I'm far > more user than developer, so if someone would like to lead the way... The IEC-61883-4 spec describes MPEG2-TS over 1394. Can you confirm that your device conforms with this? The spec description says it is related to DVB, in which case one should look strongly at the DVB API and source code at http://www.linuxtv.org/. What devices support this that might convince me to buy one--a digital TV? > -Zandr > -- > --------------------------------------------------------------------- > Aleksandr Milewski N6MOD > n6...@mi... http://www.milewski.org/ > > _______________________________________________ > mailing list Lin...@li... > http://lists.sourceforge.net/lists/listinfo/linux1394-user > |
From: Aleksandr M. <n6...@mi...> - 2001-02-06 20:58:06
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At 12:49 PM -0500 on 2/6/01, Dan Dennedy commanded the electrons to create a missive titled "Re: MPEG-2 Capture?": |From: "Aleksandr Milewski" <n6...@mi...> |> This is the right thing to do. I'll look at the source, but I have a |> suspicion that commenting out large pieces of dvgrap might be the way |> to go. | |There is a test mode of dvgrab and corresponding function that you should |look at for the case that is closest to yours. It will be a couple of weeks before I can get that machine built (too many commitments at work) but when I get that running I'll take a good look at dvgrab and both test and raw modes. I read the docs last night, and I rather got the impression that test mode would include the 1394 headers in the file. I guess I don't understand the difference between test mode and raw mode. |The IEC-61883-4 spec describes MPEG2-TS over 1394. Can you confirm that your |device conforms with this? The spec description says it is related to DVB, |in which case one should look strongly at the DVB API and source code at |http://www.linuxtv.org/. I'm fairly sure that they aren't that sophisticated, but at this point we're speculating. Probably the best thing for me to do is build up a machine with 2.4 and linux1394, and make a test mode file available to those who know more than I do. |What devices support this that might convince me to buy one--a digital TV? At the moment, there's nothing on the market. The first generation of D-VHS decks all had one form or another of this, although things were somewhat proprietary. Hughes and RCA DirecTV receivers would play with each other, and Panasonic did their own thing. I think the tape format was the same (14.1Mbps MPEG2-TS) but the 1394 implemenations were (deliberately?) incompatible. The Hughes/RCA devices were SD only, but the Panasonic PV-HD1000 DVHS VCR can record all 18 ATSC formats. The way these thing worked was that the bitstream would get sent down the 1394 to the VCR during record, and back up the 1394 to the MPEG2 decoder in the set top during playback. You could dub from tape to tape by connecting two machines over 1394. All of these got yanked off the market over the past six months, presumably under pressure from the MPAA. There's a new generation of D-VHS machines that were announced at CES this year, but with some form of copy protection to keep Hollywood happy. I want to be able to capture from a D-VHS deck to a file so I can edit the programs, and then burn to DVD-R for archiving. -Zandr -- --------------------------------------------------------------------- Aleksandr Milewski N6MOD n6...@mi... http://www.milewski.org/ |