On Sat, 29 Jul 2006 19:35:19 -0300 "Marlon Brandão de Sousa" <[EMAIL PROTECTED]> wrote:
[...] > I decided first to preprocess the contrast and brigtness in the avi > file generating a pre processed avi file and after this encode the pre > processed file into an 3gp one. In order to preserve the maximum possible source qulity, I always recommend to do the least amount of transcoding possible, so from my own modest viewpoint the best strategy will be to 1) transcode directly your source material into mpeg4-on-avi applying corrections on the fly (transcode should be fine for this step) 2) translate mpeg4/avi into final format by just changing the container (here ffmpeg could help since it supports way more containers, yet). [...] > There I read I need to know what codecs my avi file contains before > trying to run transcode. Well, transcode has some (fair) autodetection facilities that are supposed to save users from this task :) Anyway, to know what we're going to transcode isn't a bad idea :) > tcprobe -i gol.avi > [tcprobe] RIFF data, AVI video > [avilib] V: 29.970 fps, codec=MJPG, frames=450, width=320, height=240 > [avilib] A: 48000 Hz, format=0x01, bits=16, channels=2, bitrate=1536 kbps, > [avilib] 451 chunks, 2882880 bytes, CBR > [tcprobe] summary for gol.avi, (*) = not default, 0 = not detected > import frame size: -g 320x240 [720x576] (*) > frame rate: -f 29.970 [25.000] frc=4 (*) > audio track: -a 0 [0] -e 48000,16,2 [48000,16,2] -n 0x1 [0x2000] (*) > bitrate=1536 kbps > length: 450 frames, frame_time=33 msec, > duration=0:00:15.015 > > The strange thing is that it didnt show the audio codec used in the > .avi file. It shows, but in a cryptic form (yeah, this should be improved too). See the third line of output, the format=XXX field. Here we have a PCM audio track (no encoded): 0x01 -> PCM > Ok, now I know my video is mjpg and audio is pcm. So what I want is to > generate another .avi file, with the same size, with mjpg and audio > pcm, with the same size, etc ... with contrast and brightness changed. OK, there is some options and filters that hopefully could help you -G, pp filter, yuvdenoise filter, maybe xsharpen filter too. Warning: all filter above are VERY cpu-hungry. Hope This Helps, Best regards -- Francesco Romani - Ikitt ['people always complain, no matther what you do'] IM contact : (email first, Antispam default deny!) icq://27-83-87-867 known bugs : http://www.transcoding.org/cgi-bin/transcode?Bug_Showcase tiny homepage : http://fromani.exit1.org (see IDEAS if you want send code!)
