ffmpegX website confusing on quality/benchmarks - comments?

[broaddd]

Firstly, ffmpegx is terrific and I gladly donated to the author as I use it all the time.

Secondly, some of my comments might relate to a lack of knowledge, but some comments arise from what do seem to be confusing or contradictory comments on the website which I hope someone might clarify.

The website says 'use [MPEG-4 AVI ffmpeg] when speed is your first choice' and that it is 'one of the highest quality MPEG-4 codecs around'. In the next paragraph it says '[MPEG-4 AVI mencoder] is significantly slower than the ffmpeg engine.' Later, it says 'ffmpeg engine "XviD" codec uses the same encoder core as mencoder XviD, though it benefits from overall ffmpeg speed and can be up to 300% faster than mencoder XviD.'

But on the benchmarks graph page it shows that [MPEG-4 AVI mencoder] is about 33% faster than the ffmpeg version; and that mencoder XviD is about 10-20% faster than ffmpeg XviD.

It would be useful if the website had a clearer guide on which codec to use for high-speed encoding with reasonable quality; and perhaps screenshots of how different codecs render the same sequence.

For example, is the benchmark example of [MPEG-4 AVI mencoder] with HQ, trellis, b-frames, bi-linear, SSE settings going to give you (generally) equal or better results to XviD with no extra options? Because the benchmark page suggests that [MPEG-4 AVI mencoder] with those settings will be about as fast or faster than plain old XviD.

Regards,
Bruce
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PB 1.67ghz 1024mb 100gb 5400rpm 128mb ATI[/i]

[major]

The benchmark is correct, the comment you found (in which page? I will change it) referred to older versions when mencoder was slower. About comparing quality over formats, there is no quantitative method, so you should compare by looking at the result. Personally I find the difference quite minimal.

[broaddd]

Hi, the comments are on http://homepage.mac.com/major4/video.html.

I know this is a subjective judgement, but looking at two encoding options on the benchmark page:

1. mencoder mpeg-4 avi with HQ, b-frames, Trellis, Bilinear, SSE; and
2. xvid (without the HQ etc).

The benchmarks on the site show these as roughly similar in encoding speed. Do they generally have similar encoding quality? Because if so, I guess turning on HQ etc in XviD will give even higher quality but slower time.

Thanks major!

B

[major]

There is no simple quantitative method to answer this question so it must be answered by looking at the images. Personally I hardly find any difference between 1. and 2.