Converting WTV to DVR-MS

[Mike88]

I just used WMC7 to convert a WTV file to DVR-MS & then went to edit out the commercials using VideoReDo & noticed the evening News had no audio. Not that it really mattered since it was going to get cut. But I wondered what was happening so did some searching & found this.
http://answers.microsoft.com/en-us/wind ... e8548c6d30

This made me question what kind of audio my video now had so I checked a few things using MediaInfo & here’s what I found.
The original WTV file & the subsequent DVR-MS file have no audio listed. The edited DVR-MS video was saved as a DVR-MS file & it too had no audio listed. However all these videos actually did have audio, except where the News was concerned.

So I saved the edited video as an MPG file & MediaInfo displayed this for the audio.
Audio
ID : 189 (0xBD)-128 (0x80)
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : VI (visually impaired)
Muxing mode : DVD-Video
Duration : 1h 4mn
Bit rate mode : Constant
Bit rate : 128 Kbps
Channel(s) : 1 channel
Channel positions : Front: C
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy

It appears that while WMC7 can convert the video so that I can edit it, it can also screws up the audio. Maybe an updated version of VRD that accepts WTV files will not have that problem. That leads to a question - what are the pros & cons regarding saving the edited video in WTS vs DVR-MS vs MPG?

[Crash2009]

Where are you trying to get to with this Mike? Maybe someone has a shortcut for you.

or, are you just chopping these files up for fun?

[Mike88]

I was editing an OTA recording & just happened to notice the DVR-MS file had no audio when the evening News was playing. That made me question the main program's audio, which it turns out was not proper because the WMC7 conversion process cannot handle more than one audio stream. That in turn made me think about what format I wanted the final video to be in.

This morning I just upgraded to the latest version of VRD and it handles the conversion & audio without a problem. However it has 20 options to save in so now I'm really confused.

I've read that H.264 kept file sizes relatively small & that MP4 was widely accepted. So I thought I tried saving a video using those parameters. That was a mistake. I realize there's going to be some conversion taking place but didn't expect all 4 cores of my CPU to run at 90%. And the processing status bar barely showed movement.

So I guess it's best to stay in MPEG-2. But I'm not sure at this point whether to save as .wtv, .dvr-ms, .mpg, .ts, .m2ts, .mkv. What I need is a chart showing the advantages & disadvantages & when to use some of the file formats. I'd like to use a widely accepted format & still have it work seamlessly with WMC7, if that's possible.

[Rainey]

Mediainfo does not read the WTV files correctly so that is the first problem.

The WTV file may have more then one audio track and most likely does. The first track is normally AC3 and the second SAP track may not be English.
Viedoredo has a option to select only one of the audio tracks, and i think it failed if you had multiple audio track without special processing.

If you do convert the video if you select the correct multiple in reduced size the speed of the conversion may be much faster. I seemed to like Videoredo but the license keep claiming i need to redo it and the program would just be a PITA when it would not run and need the license fixed again.

So i started using MCEbuddy and it has a Xbox profile that gets good quality output and a small file size and the speed of conversion was not to bad. The best part was it is all automatic, you set it up and just drop files in a folder and they get processed.

[DSperber]

This morning I just upgraded to the latest version of VRD and it handles the conversion & audio without a problem.

As you've now discovered, the latest VideoRedo TV Suite v5 handles WTV natively as input. So it can read the WTV output from WMC immediately and directly. No need to convert it to DVR-MS first.

However it has 20 options to save in so now I'm really confused.

No need to be confused. What you save it in depends on what you want to do with the saved edited clips/programs, and how you're eventually going to be playing them. It also depends on whether or not you're concerned with the audio/video quality of the saved edited clips/programs, and also whether or not you're concerned about file size at all. Finally, it depends on whether or not you care about how much time (and CPU processing horsepower, and related electricity usage and generated heat and cooling fan noise) you don't mind spending to produce your saved edited clips/programs.

These are all factors that influence what format you choose to save the edited clips/program video files as. But to begin with you simply must realize that you're starting from MPEG-2 encoded data, inside a WTV wrapper that supports copy-protection. So, first, you can only edit copy-freely WMC-produced WTV content (e.g. OTA ATSC broadcast programs from a roof antenna if that's the TV tuner you have, or from clear-QAM content provided by your cable company).

After that, it's up to you... depending on your eventual usage criteria, to decide which available format to use for the saved clips.

I've read that H.264 kept file sizes relatively small & that MP4 was widely accepted. So I thought I tried saving a video using those parameters. That was a mistake. I realize there's going to be some conversion taking place but didn't expect all 4 cores of my CPU to run at 90%. And the processing status bar barely showed movement.

So I guess it's best to stay in MPEG-2. But I'm not sure at this point whether to save as .wtv, .dvr-ms, .mpg, .ts, .m2ts, .mkv. What I need is a chart showing the advantages & disadvantages & when to use some of the file formats. I'd like to use a widely accepted format & still have it work seamlessly with WMC7, if that's possible.

Yes, "rendering" that involves re-compressing from the original underlying MPEG-2 necessarily takes huge CPU horsepower to accomplish, not to mention the amount of time to complete. Years ago I created my own authored BDMV (using multiAVCHD and IMGBurn) composed of 44 "clips" which were originally AVI files. The production of the authored BDMV compilation (including 44 titles, and related subordinate chapters in each title) took a total of 31 straight hours of "rendering time"!!! That's right, my CPU was at about 100% for 31 hours!!!

Well, if you ask VRD to do this same type of thing, to re-compress the original MPEG-2 data into some other compressed format (e.g. H.264, MP4), it just needs to burn the CPU until that re-compression is complete. If smaller file size is your prime criteria, and that's not up for discussion, I guess you have to pay the one-time price to get the job done. If you're lucky (e.g. if your source is HDTV quality to start) the re-compressed results will be quite good (although any re-compression involves now picking "output quality vs. size/time-to-produce" parameters, so you're again up against many decisions that are relatively arbitrary), but with the wrong re-compression parameters chosen (to save time or save file size) the results can be quite poor relative to the original HDTV source.

On the other hand... if you don't care about output file size, and you do care about "best possible quality" (and nothing can be better than a 100%-duplicate bit-perfect edited clip version copy of the original MPEG-2 HDTV source), then you for sure should retain the original MPEG-2 underlying data format in your output edited clip format rather than choosing another compression method, e.g. H.264. That means NO RE-COMPRESSION WILL BE DONE AT ALL, so absolutely zero CPU time will be used to re-compress. Your edited clips will then be able to be played by any player program (or mechanical disc player, if you burn to authored BDMV for example) that can support MPEG-2 data.

So the only thing VRD is actually then doing is to change the "wrapper" format around the MPEG-2 data, from WMC-produced WTV to some other wrapper. I, myself, always use MPG as the "wrapper" (with the original untouched original 100% bit-perfect MPEG-2 source data simply re-wrapped inside MPG), because effectively 100% of all Windows and 3rd-party media viewer player software products accept MPG wrapper format. And Win7 has built-in native support for MPEG-2 decoding of the data inside the MPG wrapper.

Finally, because no re-compression is required (if you choose MPG wrapper and retaining MPEG-2 format for the VRD output) then VRD does what it calls "fast-frame copy" of the underlying MPEG-2 data, simply re-wrapping the WTV original of MPEG-2 into new MPG-wrapped MPEG-2 duplicate. It takes hardly any time at all to accomplish (I mean depending on the size of your edited clips and speed of your machine, VRD can take just a few seconds to maybe under a minute, and it's all done).

These MPG/MPEG-2 clips of copy-freely HDTV source in WTV format originally recorded by WMC, can be played by both WMC as well as WMP as well as WMC as well as by any other 3rd-party media player software (e.g. VideoLan VLC, PotPlayer, etc.).

So if highest possible resulting video quality is important to you (and nothing can be better than a bit-perfect 100% digital exact duplicate of the original HDTV program), and if speed of "saving" is important to you, and if file size of the result is NOT important to you, then choosing your output format as "MPEG-2 Program Stream (*.mpg)" is what you want to save your edited clips as. Just remember you've produced an edited bit-perfect exact duplicate edited clip of the original HDTV source program. So if it was 1080i source it's 1080i in the clip, 720p source is 720p in the clip... exactly the same digital MPEG-2 digital video and AC-3 (DD5.1) digital multi-channel audio as the original.

You can then use these MPG/MPEG-2 clips to play back from hard drive, or as input to something like multiAVCHD to produce authored BDMV ISO files that can be burned to BDMV blank media, etc. And when the authoring to ISO is done, once again a product like multiAVCHD can be told (through settings) that you do NOT want to re-compress, but instead you simply want to "fast-copy" to ISO. So just like with VRD that has its "fast-frame copy" behavior when no re-compression is involved, multiAVCHD will also do its own "fast copy" from your MPG/MPEG-2 clips to the ISO compilation. You'll end up with 100% bit-perfect digital duplicates of your HDTV original programs with original HDTV quality, on your burned BDMV discs.

Again... file size cannot be a consideration, if you chose MPG/MPEG-2 as your output format from VRD. You must want absolute best-quality (i.e. 100% untouched original HDTV bit-perfect digital duplicates) audio/video clips, for absolute best-quality playback from hard drive MPG or from burned BDMV, exactly like the original HDTV source. If BEST POSSIBLE AUDIO/VIDEO QUALITY is what you want, then MPG/MPEG-2 is your best bet. And you'll get the job done with almost no CPU usage, in seconds.

[Mike88]

DSperber -
Thanks for the reply & information.

File size is not important because I rarely save anything & therefore have lots of HDD space free.

Quality is very important. Since file size is not important I want the best quality.

It would be nice to have the format compatible with other systems. If I ever get a PC with Windows 10 for example, which looks like may not use WMC, will the video still be playable. If I have a choice I'd rather not box myself into a corner.

I read somewhere that WMC can use more functions such as "Skip" or "FF" or similar functions if the video is in a DVR-MS and/or WTV format. I don't know if that's true. It's been a while since I played an .mpg video on the HTPC & don't recall which player I used. I'll have to try it using WMC & how it works.

[DSperber]

VideoRedo can save edited WTV/MPEG-2 input files with the same WTV wrapper. That's one of the save-as format options, along with MPG/MPEG-2, TS/MPEG-2, etc.

If you save the edited clips as WTV then it would be playable by WMC as "recorded TV". If you save the edited clips as MPG then it would be playable by WMC as "video". WMC can play both types, but it's just separate.

WMP can also play both types, as can VLC, PotPlayer, etc. But not all media players can play files in WTV wrappers, whereas ALL media players can play MPG files. So again, you don't need to use WMC to be your exclusive player... you can use any media player.

Most importantly, if you want absolute best-quality and file size is not an issue, then you absolutely want to NOT RE-COMPRESS the underlying MPEG-2 content. You simply want to edit out whatever you want to edit out, and save the edited result suitably. Again, I recommend MPG/MPEG-2 because of its universal usability. You will have 100% identical HDTV content to the original source program, but in an MPG wrapper.