HDV and FFmpegX

[dylanpank@msn.com]

I don't know if anyone has had a chance to play around with the demo files of new sony HDV 1080i footage that are available on the net. Out of curiosity I tried processing them with FFmpegX. While not a completely exhaustive series of tests, i did try demuxing the m2t (raw HDV mpg2 transport streams) but FFmpegX wouldn't have it, only wanting to deal with .vob or.mpg files. .m2t streams are basically just mpeg2 with mp2 audio (albeit 1440x1080i mpeg with 384kbs mp2 audio) so they should demultiplex into .mp2 and .m2v and it seams that there are tools to do this out there.

Next I tried loading the .m2t files into the main processor. Better success this time but still hit and miss. FFmpegX loaded the files and even recognised them as mpeg2 and mp2. I tried exporting to DV - with some files this worked perfectly, with somefiles it seemed to distort and others it buggered up the frame rate, but with about half the files I had it failed completely, mentioning a codec missmatch in the terminal.

I think it would be a big feather in FFmpegX's cap if it was the first shareware tool to properly support HDV. FFmpeg doesn't seem to support proper interlaced scaling unless I am missing something. These means in scaling 1080i to DV i had to de-interlace (fine for me now, but inm the long run a limitation). Proper interlaced scaling seems to be the next desireble step. Is there any chance HDV support would be feasable in future.

[major]

ffmpeg supports HD quite well. The "codec type mismatch" message has nothing to do with the source being HD, it is rather inverted video/audio mapping so you should simply enable "invert mapping" in the audio tab.

[Wibbler]

I used ffmpegX with the HRHD copies of the new enterprise series, to put them on DVD - it works quite well..

W

[dylanpank@msn.com]

Major, thanks for the tip - I tried it and you are right, in fact about half the clips have inverted audio/video streams. I guess that is due to some problem with the originally captured files, I gather the capture proram doesn't officially support 1080i at this point. there wasn't any particular rhyme or reason to which ones needed inverting Have you tried them yourself yet?

I must say that the ability to demux the .m2t would be a great bonus, though I guess you are limited by the cli tools used within FFmpegX.

I just have to add, FFmpegX is great, so I was very pleased to see it would be usable in the HDV workflow I'm hoping to move into. In all fairness I must register it one of these days - it's just I don't require the DVD>4 feature (and I'm extraordinarily tight)

Apart from demuxing m2t the thing I would hope to see in the future is maintaining interlaced fields when rescaling, FFmpeg (I refering to the CLI tool with FFmpegX) like most tools works on a frame basis, so I guess it's pretty damn near impossible.

cheers

[csdesigns]

MPEGStreamClip 1.1 can demux transport streams into .m2v and .ac3 quite well. It doesn't cause the audio to be unusable like bbDEMUX does either. I use it all the time to do raw edits on the streams I get from my EyeTV 500.

[dylanpank@msn.com]

Thanks, MPEGStreamclip is excellent - it even has the ability to scale interlaced fields separately.

I'm using it in conjuction with FFmpegX a lot now. (Streamclip to demux and them FFmpegX to recompress)

[ssevenup]

I have been evaluating various work flows for converting terrestrial DTV streams into anamorphic DVD images. I have looked at Linux and MacOSX tools since my house is a Microsoft free zone. ffmpeg appears to be able to convert 720p streams if I first use MPEG Streamclip to convert the transport stream to a muxed mpeg. If I don't convert first I have not had success. I also looked at splitting with MSC to m2v/ac3 first but had mixed success there too. Terrestrial HD streams generally have some issues when you get dropouts and such. This story is coming out in random order I realize. Have others here found a workflow that produces reasonable DVD images from terrestrial 480, 720 and or 1080 streams?

--MM

[csdesigns]

What's your capture device? Because, first of all, HDV is not the same as terrestrial TV. Its very different in fact, even if both are MPEG-2 transport streams. Your capture device could matter a great deal in this case.

[ssevenup]

What's your capture device? Because, first of all, HDV is not the same as terrestrial TV. Its very different in fact, even if both are MPEG-2 transport streams. Your capture device could matter a great deal in this case.

pcHDTV's HD-3000

The pcHDTV Hi Definition PCI card is based on Oren Semiconductor's ATSC receiver chip and Conexant's CX23883 NTSC receiver chip providing excellent HD and SD reception.

www.pchdtv.com

Too many acronyms for that time of the night

[csdesigns]

OK. ATSC is very different than HDV, so some tools that are geared towards HDV, may or may not work with ATSC. For the most part, MSC does work. But I have encountered a number of streams MSC (or any other utility, mac or PC) could not handle. The only app that even seems to even recognize all streams correctly is VLC. But I have been unable to demux some (likely the same issue you're having) of these with MSC or XMuxer for PC. Some streams use encryption, that allows you to capture and watch from your PC, but won't allow demuxing or alteration of the transport stream. Its possible this is what you are experiencing, although it is more likely that there are packet breaks in the signal that is causing the errors. And the sad answer to that, to my knowledge, is that there is not yet a reliable solution on mac, linux, or pc.

If editing and recompressing ATSC is really important to you right now, the best option for any platform is an EyeTV 500. I have never had a problem converting captures that I get with. Unfortunately, it does not work with streams captured from other devices.

[ssevenup]

If editing and recompressing ATSC is really important to you right now, the best option for any platform is an EyeTV 500. I have never had a problem converting captures that I get with. Unfortunately, it does not work with streams captured from other devices.

Very helpful comments, thanks very much

--MM

[BJ_M]

another really good de-muxer that works is ][Muxer by moonlight cordless


http://www.elecard.com/download/#Xmuxer

http://www.elecard.com/ftp/pub/Xmuxer/Xmuxer.zip


the demo version is full version and doesnt seem to ever expire

[csdesigns]

Yes, I mentioned that above. The Pro version that is in pre-release form is better, but even XMuxer has problems with some streams, particularly streams with data breaks. It is PC only BTW.