Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx> writes: > Em 02-06-2010 18:09, Andrew Morton escreveu: >> On Sun, 30 May 2010 14:29:55 GMT >> bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: >> >>> https://bugzilla.kernel.org/show_bug.cgi?id=16077 >> >> 2.6.33 -> 2.6.34 performance regression in dvb webcam frame rates. > > I don't think this is a regression. Probably, the new code is allowing a higher > resolution. As the maximum bandwidth from the sensor to the USB bridge doesn't > change, and a change from QVGA to VGA implies on 4x more pixels per frame, as > consequence, the number of frames per second will likely reduce by a factor of 4x. > > I've asked the reporter to confirm what resolutions he is setting on 2.6.33 > and on 2.6.34, just to double check if my thesis is correct. Well, the two video clips attached to the bug shows the same resolution but a much, much lower video (and overall) bitrate in 2.6.34. Output from mediainfo: General Complete name : 2.6.33-02063303-generic #02063303.ogv Format : OGG File size : 672 KiB Duration : 6s 331ms Overall bit rate : 870 Kbps Video ID : 20423689 (0x137A409) Format : Theora Duration : 6s 333ms Bit rate : 714 Kbps Width : 320 pixels Height : 240 pixels Display aspect ratio : 4:3 Frame rate : 30.000 fps Bits/(Pixel*Frame) : 0.310 Stream size : 552 KiB (82%) Writing library : Xiph.Org libtheora 1.1 20090822 (Thusnelda) Audio ID : 1459180980 (0x56F955B4) Format : Vorbis Format settings, Floor : 1 Duration : 6s 331ms Bit rate mode : Constant Bit rate : 112 Kbps Channel(s) : 2 channels Sampling rate : 44.1 KHz Stream size : 86.6 KiB (13%) Writing library : libVorbis 20090709 (UTC 2009-07-09) General Complete name : 2.6.34-999-generic #201005121008.ogv Format : OGG File size : 276 KiB Duration : 15s 424ms Overall bit rate : 146 Kbps Video ID : 12773534 (0xC2E89E) Format : Theora Duration : 15s 433ms Bit rate : 19.8 Kbps Width : 320 pixels Height : 240 pixels Display aspect ratio : 4:3 Frame rate : 30.000 fps Bits/(Pixel*Frame) : 0.009 Stream size : 37.2 KiB (14%) Writing library : Xiph.Org libtheora 1.1 20090822 (Thusnelda) Audio ID : 1010301390 (0x3C37F9CE) Format : Vorbis Format settings, Floor : 1 Duration : 15s 424ms Bit rate mode : Constant Bit rate : 112 Kbps Channel(s) : 2 channels Sampling rate : 44.1 KHz Stream size : 211 KiB (76%) Writing library : libVorbis 20090709 (UTC 2009-07-09) Bjørn -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
