Seeking Broad Downsampling Advice

[enter8]

Recently, I inherited a DVD collection from a relative. Along with the physical discs, he had ripped/backed up pretty much everything to a variety of formats, sometimes multiple formats. It's almost all either 1080p or 720p (or both). My older computer can't really handle either so I'm considering re-encoding them to either 576 or 480.

I spent the better part of yesterday looking for tutorials and the ones I find tend to be either outdated, too simplified (one click) or more geared towards other types of encoding. While I know that I'm not going to find anything that spoon feeds me everything, some rough brush strokes would help cut through the clutter.

My goal is good transcodes. Not the best transcodes in the world, just watchable. I was able to do a one click transcode with Megui that was surprisingly watchable, but I want to have more control over the process than that.

Any advice would be appreciated.

[jagabo]

Try using ffmpeg in a batch file:

"C:\ffmpeg" -i %1 -vf scale=w=-4:h=480 -c:v libx264 -preset veryfast -crf 20 -c:a copy "%~dpn1.480p.mp4"

You can just drag/drop any source video onto the batch file. The video will be downscaled and reencoded with h.264 keeping the original audio. Change the path to ffmpeg.exe to wherever you put it on your computer. In this example ffmpeg.exe is in the root of drive C.

You can adjust the frame size by changing h=480 to h=576 (or whatever value you want). w=-4 makes the width the nearest mod4 size that will keep the correct aspect ratio.

veryfast specified x264 veryfast preset -- not the best quality but pretty fast (since you have a very slow computer). The available presets are ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, veryslow, placebo. Generally, quality gets better, and file size gets smaller, as you go from fast presets to slow presets. Use the slowest preset you can stand.

crf 20 is moderate quality (the encoder will use whatever bitrate is necessary to achieve that quality). Lower values will give higher quality (and larger files). Higher values will give lower quality (and smaller files). Sane values for videos you plan to watch are 15 to 25.

The output name will have .480 added just before the extension. For example a file like Video.mp4 will converted to Video.480.mp4 (in the same folder). If you want mkv instead of mp4 just change the output spec from mp4 to mkv.

An old Athlon 2 x2 255 here downscaled an 80 second 1920x1080 23.976 fps video to 852x480 in about 60 seconds with those settings.

[poisondeathray]

Did you try HW acceleration for playback? That 7300GS supports an early Nvidia PureVideo generation, but it should at least partially support AVC and MPEG2 playback .

Even if only some of the formats were supported , that would be fewer videos to convert, and you could watch them at full resolution

[jagabo]

I forgot to metion this: if all those 720p and 1080p videos were made by upscaling the DVDs you'll probably get better results by converting the original DVDs rather than downscaling the upscaled videos.