On Wed, Mar 14, 2018 at 22:01:01 +0100, Adi Marvillo wrote: > ffprobe does not show any difference in the file-specs: not with the > encoder nor in resolution although the small video has bad quality- Does > anybody know what is the differnce between the 2 files and why ffmpeg > keeps telling me that everyting is the same in both files?
Is that so? My ffmpeg tells me that things are quite different: barsnick@sunshine:~/tmp > diff -u <(ffmpeg -i testfile_small.vob 2>&1) <(ffmpeg -i testfile_big.vob 2>&1) --- /proc/self/fd/63 2018-03-15 17:19:52.992464532 +0100 +++ /proc/self/fd/62 2018-03-15 17:19:52.992464532 +0100 @@ -9,8 +9,8 @@ libswscale 5. 0.102 / 5. 0.102 libswresample 3. 0.101 / 3. 0.101 libpostproc 55. 0.100 / 55. 0.100 -Input #0, mpeg, from 'testfile_small.vob': - Duration: 00:00:20.02, start: 0.529978, bitrate: 1012 kb/s - Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, progressive), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc - Stream #0:1[0x1c0]: Audio: mp2, 48000 Hz, stereo, s16p, 384 kb/s +Input #0, mpeg, from 'testfile_big.vob': + Duration: 00:00:19.97, start: 0.500000, bitrate: 7258 kb/s + Stream #0:0[0x80]: Audio: ac3, 48000 Hz, stereo, fltp, 224 kb/s + Stream #0:1[0x1e0]: Video: mpeg2video (Main), yuv420p(tv, top first), 720x576 [SAR 64:45 DAR 16:9], 25 fps, 25 tbr, 90k tbn, 50 tbc At least one output file must be specified > both cutting commands: > ffmpeg -i Video.vob -ss 00:10:00 -t 00:00:20 > ~/Dokumente/test/testfile_small.vob Here, ffmpeg re-encodes with default parameters. For VOB, that's mpeg2 video (with a very low default bitrate) and mp2 audio. You need to tune the encoding to get better quality (likely at the cost of larger files, unless you choose more modern codecs). > ffmpeg -i Video.vob -ss 00:10:00 -t 00:00:20 -c:v copy -c:a copy > ~/Dokumente/test/testfile_big.vob Here, ffmpeg retains the original streams, with their original codecs and bandwidths, no quality loss. You didn't show us your command output. If you had, we could have pointed out to you that the encoding ffmpeg also shows quite different things in the console log. Moritz _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
