HydrogenAudio

Digital Audio/Video => Movie/Multichannel audio => Topic started by: AndyH-ha on 2021-06-05 18:53:23

Title: controlled fast forward and reverse
Post by: AndyH-ha on 2021-06-05 18:53:23
I’ve been recording broadcast TV shows to a USB hard drive, e.g.:
https://www.amazon.com/Viewtv-AT-163-Converter-Recording-Composite/dp/B00GGVPKKC/ref=cm_cr_dp_asin_lnk/182-6371267-9975751

While it is true that the offerings are rarely any challenge to intellect or wonder, some can be at least mildly entertaining when one is too tired for anything else. The advantage of this means of viewing is that I can watch anything broadcast at the time of my choosing and can easily fast forward through all those ridiculous commercials.

Currently, and for some unknown time, I am in a position of very limited resources. I have many recordings made over a considerable time span but not the facilities to view them in the most beneficial way. However, the recordings will play on a computer, such as with the VideoLAN VLC media player, but it has the same major deficiency as most (hopefully not ALL) other computer software players.

With any of the hardware recorders/playback device one has reasonable control of streaming. There are fast forward and reverse buttons that allow one to see what is passing by so that one can know where to stop. Press the button once and forward speed is 2X, again and the speed is 4X, then 8X, 16X, 32X. Of course frames are skipped in fast forward or reverse but it is still easy to see where one is going and when one arrives.

With VLC, as with foobar2000, and every other software player I know about, one drags a blind slider whose speed depends upon the length of the file being played (unless there is some control I haven’t discovered). The same is true of every hardware digital audio player I ever used but my guess is that is due to keeping the controls as simple as possible rather than as convenient as possible.

Obviously it is possible to do controlled scans on digital recordings, I’ve been doing so for years with inexpensive video hardware, but does anyone make reasonable computer software?
Title: Re: controlled fast forward and reverse
Post by: j7n on 2021-06-05 19:41:28
Video players usually have a high speed playback option. This costs CPU usage as every frame is decoded to keep it as a reference for future frames that depend on it in common high compression formats. Editing formats usually have independent frames to provide fast seeking. In Media Player Classic the speed appears to be limited to double (Play -> Increase Rate), and also works with GPU acceleration. In SMPlayer/MPV the speed can be increased by greater factors (Play -> Speed).
Title: Re: controlled fast forward and reverse
Post by: AndyH-ha on 2021-06-06 19:35:52
Those appear to be Linux software. Does anyone know any Windows software suitable for watching a movie (with the fast forward and reverse controls)?
Title: Re: controlled fast forward and reverse
Post by: j7n on 2021-06-06 20:45:56
Media Player Classic Home Cinema and SMPlayer are available for Windows. I suspect that VLC should also have a fast playback option hidden. I don't think it is practical to have reverse playback with around 200 frame group of pictures MPEG-4 file. The player would have to jump backwards, decode and keep that many frames in memory. I'd be interested to read how any player does it. With a short-GOP DVD one could get away by playing only the keyframes.
Title: Re: controlled fast forward and reverse
Post by: AndyH-ha on 2021-06-06 23:59:21
I don't know what they actually do but the hardware recorders/players I have give me the impression that each higher speed skips more frames of video for each that is displayed. This wouldn't be very good for viewing but showing every Nth frame provides enough information to navigate successfully, even at 64X. Audio is suppressed and, for video navigation purposes, is pretty much irrelevant.

The file suffix that is recorded is .mts The player lists a sizeable number of file types it will play back but I've never used it to play anything except its recordings.