Date: Sun, 6 Feb 2005 22:28:41 -0500 From: Paul Chvostek <paul+fbsd@it.ca> To: freebsd-multimedia@freebsd.org Subject: ffmpeg at half speed ... sort of. Message-ID: <20050207032841.GA33816@it.ca>
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This is weird. When I encode with ffmpeg, the resultant file appears to play back at about half the expected framerate, with the wrong bitrate. I encode with ffmpeg: encode$ ffmpeg -y -an -vd /dev/bktr0 -s 160-120 -tvstd ntsc \ -vcodec mpeg4 -b 50 -f avi -t 15 -r 29.97 test.avi And the resultant file appears to be right: encode$ file test.avi test.avi: RIFF (little-endian) data, AVI, 160 x 120, ~30 fps, video: DivX 4 And mplayer says: play$ mplayer test.avi 2>/dev/null | grep VIDEO VIDEO: [DIVX] 160x120 24bpp 29.970 fps 127.9 kbps (15.6 kbyte/s) Note the 127.9 kbps. That's at odds with ffmpeg's "-b 50". And the actual video that gets displayed seems to run in slow motion. Yet after playing a 15 second clip, mplayer shows: V: 15.0 450 1% 3% 0.0% 0 0 0% indicating 30fps. The video plays back in real time when I force the framerate to the ratio of 127.9 kbps to the 50 I specified: encode$ mplayer -fps 77 test.avi But that doesn't give me 15 seconds of video. Specs for the encoder and player are: encode$ uname -sr FreeBSD 5.3-STABLE encode$ dmesg | grep bktr0: bktr0: <BrookTree 878> mem 0xee3fe000-0xee3fefff irq 21 at device 10.0 on pci1 bktr0: [GIANT-LOCKED] bktr0: Warning - card vendor 0x0000 (model 0x0000) unknown. bktr0: Detected a DPL34193 at 0x84 bktr0: Intel Smart Video III/VideoLogic Captivator PCI, dpl3518a dolby. play$ mplayer --version MPlayer 1.0pre5try2-3.4.2 (C) 2000-2004 MPlayer Team ... The card is an AVerMedia unit with no tuner or audio, despite what it claims. Mplayer doesn't have problems with anything else. Anybody know what the heck is going on here? Thanks. :) -- Paul Chvostek <paul@it.ca>
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