On Mon, Feb 8, 2010 at 11:39 PM, Robert Swain <[email protected]> wrote: > On 09/02/10 04:49, Thomas Worth wrote: >> >> On Mon, Feb 8, 2010 at 3:15 PM, Ronald S. Bultje<[email protected]> >> wrote: >>> >>> Hi, >>> >>> On Wed, Jan 27, 2010 at 4:20 PM, Thomas Worth<[email protected]> wrote: >>>> >>>> CODEC_ID_H264 >>>> CODEC_ID_FFH264 >>> >>> FFH264 (for encoding) would be the native FFmpeg encoder, whereas H264 >>> (default) would be the x264 encoder. For decoding, it always uses the >>> built-in decoder. So none of this matters for the subject at hand. >>> >>> Regarding your original post, I'm sceptical. A simple delta between >>> the two images on your blog shows differences (dither-related?) only >>> around thearea right above the tire. Calling this dithering an >>> improvement in quality goes way too far, imo. >> >> Yeah, it's starting to look more and more like QuickTime is taking the >> liberty of adding noise to its decompression output to cover up the >> compression artifacts. Subjectively, this may increase quality / >> aesthetic value, but this should be an option. I mean, if I want noise >> I'll add it myself, thank you. I don't know if there's a way through >> the QuickTime API to disable this behavior, but there should be. > > You were also testing against Adobe After Effects and Final Cut Pro - have > you compared the output of QuickTime to those to see the difference? I would > be very surprised if a professional grade application were to add noise > without request.
It doesn't matter which app you use, because they all use the QuickTime API for decompressing QuickTime movies. Therefore, all H.264 looks identical in every application because it's all being decompressed by the same codec. Specifically, the "QuickTimeH264.component" in /System/Library/QuickTime/. Here's a trick. Remove this file temporarily: /System/Library/QuickTime/QuickTimeH264.component Now no programs will be able to render H.264 video. That's because all of them rely on this codec to provide them with decompressed output. I'd bet it's this piece of software that's adding the noise, not the ProApps nor After Effects (or any other QuickTime enabled app). _______________________________________________ libav-user mailing list [email protected] https://lists.mplayerhq.hu/mailman/listinfo/libav-user
