Hi, On 2015-09-17, at 18:45, Dave Rice wrote: >> On Sep 14, 2015, at 11:56 PM, Etienne Desautels >> <etienne.desaut...@gmail.com> wrote:
>> I will start using FFV1 to archive video for a museum and I will like to >> know what's the best settings to get smaller files. I will use version 3 >> with checksums. From the few tests I did I found that those settings were >> the best for smaller files: >> - coder 1 >> - context 0 >> - g 1 > > I believe using -g 1 would require more size than not. On the other hand this > is usually one of the parameters for ffv1 I recommend the most as it > increases the resilience of the file which is particularly relevant for > archival use. I had a few exchanges with Peter Bubestinger of the Austrian Mediathek. It's the guy who did the test suite you mention below. Here what he says about GOP: > GOP (=Group Of Pictures) is a unit very common for lossy encoding. > If GOP=1, every frame can be decoded standalone, without requiring > previous or successive frames. > If GOP>1, frames inside the GOP require the last previous keyframe > (=I-Frame) for proper decoding of the image. > > There are 2 benefits of GOP=1: > 1) Video material can be cut at any point. This is useful for > cropping/editing frame-exact. > 2) If any errors (bit-/bytewise) happen to the video, the errors do not > affect more than 1 frame/slice at max. >> I also tried 2 pass without any success. The final file were exactly the >> same size as the one created with 1 pass. And the log of the 2 pass was >> filled only with 0 except for the last number that was something like 843? > > Can you show your process? Have you tried the directions according to the > wiki? http://trac.ffmpeg.org/wiki/Encode/FFV1 Here's Peter's answer on the subject: > Dual-pass mode is currently only working for very short clips. > It's on my TODO-list to tackle that issue, but it hasn't been solved > yet, due to lack of time :( Regards, Etienne Desautels _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
