Subject: Re: Huge 'singlejpeg's - msg#00087

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Re: Huge 'singlejpeg's

Evert|Collab wrote: Hi all and first of all for your excellent work. I did some benchmarking the other day where FFMpeg sometimes came out 30 times faster than Wildform Flix, so thats amazing. Flix supports more codecs though ;) anyway, my question. When I generate a 240x180 jpeg from a video I sometimes get jpegs larger than 1MB, any idea how this can happen? This is my command line: /usr/local/bin/ffmpeg -y -i /www/sabretooth/fcs/api/data/files/8847/16_source.avi -f singlejpeg -hq -s 240x180 /www/udc/thumbs/16_12.jpg any help would be greatly appreciated grt, Evert IIRC singlejpeg means *all* the frames in the avi are decoded, then glued into one single image, which is then encoded as a jpeg. BTW is is stronly recommended to include the full command line (which you did) *and* its output in any posting. The output messages tell us, among other things, what version you use and its configure flags and the compiler you used (some versions of gcc being cursed...). If I run your command on a 1-minute MPG of mine, I get: ffmpeg -i ../utc_1800.mpg -f singlejpeg -hq -s 240x180 tumb.jpg ffmpeg version 0.4.9-pre1, build 4756, Copyright (c) 2000-2004 Fabrice Bellard configuration: --enable-mp3lame --disable-strip --enable-amr_nb --enable-a52 --enable-gpl --enable-amr_wb --enable-static --disable-shared built on Jun 15 2005 15:53:47, gcc: 2.95.4 20011002 (Debian prerelease) Input #0, mpeg, from '../utc_1800.mpg': Duration: 00:00:57.0, start: 35802.163200, bitrate: 668 kb/s Stream #0.0[0x1e0]: Video: mpeg1video, yuv420p, 352x288, 25.00 fps, 104857 kb/s Stream #0.1[0x1c0]: Audio: mp2, 48000 Hz, mono, 32 kb/s Output #0, singlejpeg, to 'tumb.jpg': Stream #0.0: Video: mjpeg (hq), yuvj420p, 240x180, 25.00 fps, q=2-31, 200 kb/s Stream mapping: Stream #0.0 -> #0.0 [mjpeg @ 0x83bd2ec]removing common factors from framerate Press [q] to stop encoding frame= 1500 q=0.0 Lsize= 4701kB time=60.0 bitrate= 641.9kbits/s video:4701kB audio:0kB global headers:0kB muxing overhead 0.000000% < 151 pktbes02 ~/internet/ffmpeg-cvs-org-mp3/sjp> la total 4724 drwxrwx--- 2 michel pkdev 4096 Jun 20 10:56 . drwxrwx--- 13 michel pkdev 4096 Jun 20 10:55 .. -rw-rw---- 1 michel pkdev 4814192 Jun 20 10:56 tumb.jpg Mmm... there *is* something screwy: xv, gimp, IE, firebird, all identify the file as a jpeg... 240x180. It should be 240x270000 or 360000x180. Right? -- Michel Bardiaux Peaktime Belgium S.A. Bd. du Souverain, 191 B-1160 Bruxelles Tel : +32 2 790.29.41

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Re: Huge 'singlejpeg's

On Mon, Jun 20, 2005 at 11:09:51AM +0200, Michel Bardiaux wrote: > Evert|Collab wrote: > >Hi all and first of all for your excellent work. > >I did some benchmarking the other day where FFMpeg sometimes came out 30 > >times faster than Wildform Flix, so thats amazing. Flix supports more > >codecs though ;) > > > >anyway, my question. > > > >When I generate a 240x180 jpeg from a video I sometimes get jpegs larger > >than 1MB, any idea how this can happen? This is my command line: > > > >/usr/local/bin/ffmpeg -y -i > >/www/sabretooth/fcs/api/data/files/8847/16_source.avi -f singlejpeg -hq > >-s 240x180 /www/udc/thumbs/16_12.jpg > > > >any help would be greatly appreciated > > > >grt, > >Evert > > > IIRC singlejpeg means *all* the frames in the avi are decoded, then > glued into one single image, which is then encoded as a jpeg. No, this is nonsense. For a typical file it would require 100 gigs of memory.. Even if you have that much swap, less than 4 gigs are addressible on 32bit archs... > Mmm... there *is* something screwy: xv, gimp, IE, firebird, all identify > the file as a jpeg... 240x180. It should be 240x270000 or 360000x180. Right? Nope. Use printf format chars in the filename with singlejpeg and it will output one file per frame, iirc. E.g. output%05d.jpg Otherwise the file will just get overwritten again and again on every frame. Rich

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Re: Huge 'singlejpeg's

Evert|Collab wrote: Hi all and first of all for your excellent work. I did some benchmarking the other day where FFMpeg sometimes came out 30 times faster than Wildform Flix, so thats amazing. Flix supports more codecs though ;) anyway, my question. When I generate a 240x180 jpeg from a video I sometimes get jpegs larger than 1MB, any idea how this can happen? This is my command line: /usr/local/bin/ffmpeg -y -i /www/sabretooth/fcs/api/data/files/8847/16_source.avi -f singlejpeg -hq -s 240x180 /www/udc/thumbs/16_12.jpg any help would be greatly appreciated grt, Evert IIRC singlejpeg means *all* the frames in the avi are decoded, then glued into one single image, which is then encoded as a jpeg. BTW is is stronly recommended to include the full command line (which you did) *and* its output in any posting. The output messages tell us, among other things, what version you use and its configure flags and the compiler you used (some versions of gcc being cursed...). If I run your command on a 1-minute MPG of mine, I get: ffmpeg -i ../utc_1800.mpg -f singlejpeg -hq -s 240x180 tumb.jpg ffmpeg version 0.4.9-pre1, build 4756, Copyright (c) 2000-2004 Fabrice Bellard configuration: --enable-mp3lame --disable-strip --enable-amr_nb --enable-a52 --enable-gpl --enable-amr_wb --enable-static --disable-shared built on Jun 15 2005 15:53:47, gcc: 2.95.4 20011002 (Debian prerelease) Input #0, mpeg, from '../utc_1800.mpg': Duration: 00:00:57.0, start: 35802.163200, bitrate: 668 kb/s Stream #0.0[0x1e0]: Video: mpeg1video, yuv420p, 352x288, 25.00 fps, 104857 kb/s Stream #0.1[0x1c0]: Audio: mp2, 48000 Hz, mono, 32 kb/s Output #0, singlejpeg, to 'tumb.jpg': Stream #0.0: Video: mjpeg (hq), yuvj420p, 240x180, 25.00 fps, q=2-31, 200 kb/s Stream mapping: Stream #0.0 -> #0.0 [mjpeg @ 0x83bd2ec]removing common factors from framerate Press [q] to stop encoding frame= 1500 q=0.0 Lsize= 4701kB time=60.0 bitrate= 641.9kbits/s video:4701kB audio:0kB global headers:0kB muxing overhead 0.000000% < 151 pktbes02 ~/internet/ffmpeg-cvs-org-mp3/sjp> la total 4724 drwxrwx--- 2 michel pkdev 4096 Jun 20 10:56 . drwxrwx--- 13 michel pkdev 4096 Jun 20 10:55 .. -rw-rw---- 1 michel pkdev 4814192 Jun 20 10:56 tumb.jpg Mmm... there *is* something screwy: xv, gimp, IE, firebird, all identify the file as a jpeg... 240x180. It should be 240x270000 or 360000x180. Right? -- Michel Bardiaux Peaktime Belgium S.A. Bd. du Souverain, 191 B-1160 Bruxelles Tel : +32 2 790.29.41

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Re: Huge 'singlejpeg's

On Mon, Jun 20, 2005 at 11:09:51AM +0200, Michel Bardiaux wrote: > Evert|Collab wrote: > >Hi all and first of all for your excellent work. > >I did some benchmarking the other day where FFMpeg sometimes came out 30 > >times faster than Wildform Flix, so thats amazing. Flix supports more > >codecs though ;) > > > >anyway, my question. > > > >When I generate a 240x180 jpeg from a video I sometimes get jpegs larger > >than 1MB, any idea how this can happen? This is my command line: > > > >/usr/local/bin/ffmpeg -y -i > >/www/sabretooth/fcs/api/data/files/8847/16_source.avi -f singlejpeg -hq > >-s 240x180 /www/udc/thumbs/16_12.jpg > > > >any help would be greatly appreciated > > > >grt, > >Evert > > > IIRC singlejpeg means *all* the frames in the avi are decoded, then > glued into one single image, which is then encoded as a jpeg. No, this is nonsense. For a typical file it would require 100 gigs of memory.. Even if you have that much swap, less than 4 gigs are addressible on 32bit archs... > Mmm... there *is* something screwy: xv, gimp, IE, firebird, all identify > the file as a jpeg... 240x180. It should be 240x270000 or 360000x180. Right? Nope. Use printf format chars in the filename with singlejpeg and it will output one file per frame, iirc. E.g. output%05d.jpg Otherwise the file will just get overwritten again and again on every frame. Rich