> [QUOTE fw-encoder-api.txt] > Name IVTV_API_ASSIGN_STREAM_TYPE > Enum 185/0xB9 > Description > Assign stream type > Param[0] > 0=Program stream > 1=Transport stream > 2=MPEG1 stream > 3=PES A/V stream > 5=PES Video stream > 7=PES Audio stream > 10=DVD stream > 11=VCD stream > 12=SVCD stream > 13=DVD_S1 stream > 14=DVD_S2 stream > [/QUOTE] > > Yes, the wiki also tels me that. But what is the difference between a > "DVD stream", a "DVD_S1" stream, a "Transport stream" or a "Program > stream"? Is it a quality setting (some "preset"), something todo with > how things are encoded, or what is it? > > Say i want to create a stack of DVD's from my home videotapes. Should i > just set streamtype to "DVD" and that that will get me the correct > everything, including a fitting "Gigabyte per hour"? As with the > standard setting, it uses something like 6 or 7 gigabytes to get just > under 2 hours of captured data - while proffesional DVD's can manage 3 > hours or so (ok, they have more room than the 4.7 GB offered by > dvd-burners, but...) I think the best answer is, "we don't know" - Remember that for many of the chips on these boards, we do not have full access to datasheets and documentation and much of what we've been doing is based on the following: 1) Tidbits of documentation - in some cases (see discussions of the history of support for the Samsung tuners present on PVR-500 boards) we have no documentation whatsoever. It's hard to provide documentation to ivtv users that the developers don't even have. 2) Logging of what the Windows drivers do and reverse engineering this functionality (This is how initial Samsung tuner support was written) 3) Trial and error guessing (This is how tweaks to the Samsung tuner support were made, and how debugging of the "bad lowband performance on the first tuner" problem is being performed, although in this case it is lack of board-level documentation from Hauppauge beyond visual inspections that is holding us back.
Of course, given the info up there, some educated guesses can be made: Transport stream - Standard MPEG-2 transport streams, which is a container format around MPEG-2 encoded video and audio. Usually only used for transport of an MPEG-2 stream over some form of network layer such as 1394 or one of the many digital television standards. While the ivtv boards can generate these streams, almost no one will actually use them, as they are not as space efficient as other streams (they are designed to have redundancy in the case of data loss). If you see a file name with a suffix .ts, it's probably one of these. Program stream - The basic container format used by most MPEG-2 video. This is the format that MythTV saves recordings from ivtv boards in. Most ".mpg" files are some form of program stream. DVD Program Stream - Essentially a specific subset of the standard MPEG-2 program stream. Anything that can play back generic program streams should be able to play these back. I'm not sure, but I think the firmware may put restrictions on various settings such as the maximum bitrate in this mode. DVD_S1 and DVD_S2 - Unknown variants of the DVD Program Stream. PES video or audio are raw MPEG-encoded video or audio Essentially a standard program stream will contain one or more of each of these within its container format. Usually people save these with extensions like .m2a and .m2v VCD and SVCD are (I believe) very strict and possibly modified subsets of a program stream. Note that VCD video is MPEG1. Gigabytes per hour can be calculated (roughly) from the bitrate settings. Most of my recordings are 2.4 GB/hour, but I use very high average (6.5 Mbit/second I think?) and maximum (8 Mbit/sec) peak bitrates. (Note, I believe the firmware will allow you to go over 8 Mbit/sec peak even in DVD PS mode, but this WILL make some DVD players choke, I believe 8 is the maximum allowed in the DVD spec). Also keep in mind that in the past, even if you selected DVD PS, firmware bugs (which we have ABSOLUTELY no control over) would result in program streams that would make dvdauthor choke unless you remuxed the audio and video. There's nothing the ivtv devs can do about this, what Hauppauge (or another board vendor) has provided is what we've got as far as firmware is concerned. _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
