Hello, 2010/6/23 shenyue <shen...@magima.com.cn>: > Hi everyone, > > Previously I post this question on wine-user forum, seems nobody > answered/interested, so I post it here. Hope somebody give me > a hand :) > > I have some questions about wine video capture andrendering. > > I'm a newbie to wine, and am working on QQ or any other messengers in wine. > My environment is : ubuntu 10.04, installed wine 1.1.42 (later when I modify > code, wine-1.1.42's source instead), QQ2009. And during my debugging, I also > check some source code from latest wine 1.2-rc4. > > Although QQ's level is "garbage", but fortunately it works almost fine under > wine, including login, text chat, ..... But the video call can only > partially work.I can see my friend's(he's under windows of course) video, > while I can't see my preview video, and he cannot see mine video too. > And no audio at all. (Audio is another issue, I haven't deal with it now.) > > As a comparison, I run GraphEdt to check what's wrong with video capture and > rendering, my filter graph=video capture + video render. when I 'use clock', > the same thing happens, no video rendering at all, but when I DONOT > 'use clock', video rendering works fine. > > Then I read the source code and find out one problem(maybe right, maybe > wrong), when wine/dlls/qcap/v4l.c send media samples to downstream filters, > it do not set any timestamp on it. Thus if I use VideoRenderer as I did in > GraphEdt, the video render got wrong start and stop reference time for > media sample, and then the synchronisation result will be very strange. > So I modify the v4l.c and set proper timestamp on media sample. Good result, > even when I 'use clock', the capture+render graph works find in GraphEdt. > > But when I turn to QQ, my video capture+preview+encoding graph still seems > don't work. I only made it work for msn messenger a long time ago, in 6.2 or so. I'm surprised it still works. Only change since then has been adding support for libv4l. (v4l2 with v4l1 api)
> Then I checked msdn for these things, according to msdn: > "Video frames from a preview pin (as opposed to a capture pin) are not time > stamped. Because of graph latency, a video frame that is stamped with the > capture time will always arrive late at the video renderer. This may cause > the renderer to drop frames, in an attempt at quality control." > "Quality control is a mechanism for adjusting the rate of data flow through > the filter graph in response to run-time performance. If a renderer filter > is receiving too much data or too little data, it can send a quality > message. The quality message requests an adjustment in the data rate. > By default, quality messages travel upstream from the renderer until > they reach a filter that can respond (if any)." > > I've cheked winedbg log, QQ's filter graph looks like: > vfw capture filter + QQ's own video render filter + ... + ddraw/d3d7 > rendering. > QQ did not use smarttee, preview pin, standard VideoRender or > VideoRenderDefault or VideoMixingRender9 (because QQ never query > their id). Instead, I guess QQ write a video render filter by itself, and in > QQ's render filter, it directly use ddraw/d3d7 surface to render, and maybe > it does something similar to smarttee, to output to preview and encoding > at the same time. Could it be a ddraw/d3d7 failure rather than a wine failure? > Since QQ did not use preview pin directly, at first I guess maybe 'not time > stamped' is not correct, so I add some timestamp to capture's output > video frame, still no preview occurs, but result in continuous > IQualityControl interface query, but even latest wine-1.2-rc4 has not > implemented IQualityControl, so I guess, still something wrong in > timestamp synchronisation, and QQ's video render want to use > IQualityControl to fix it which wine doesn't support, so maybe > every frame is dropped, this result in my black preview video window. > I read from wine docs/wiki, once before windows messenger (8.1?) worked fine > in wine, I guess since you have written qcap/vfwcapture, of course somebody > has used wine for camera+preview+maybe encoding before, why it succeeded > by then, but fail now? > Is there anything wrong for me? Because originally I only wrote it to work with msn messenger 6.2 ;). > Btw1: there's a bug in wine-1.1.42's dlls/quartz/memallocator.c, > MediaSample's GetTime() return value is wrong, I've fixed that bug > according to latest wine, but still no video preview, and my friend cannot > see my video. > > Btw2: since qcap only works for v4l1, I ran flashcam to convert v4l2 to > v4l1. But I still wondering, since Maarteen original code supports v4l2, why > it > result in only support v4l1 (but not both v4l1 and v4l2)? Sort of, I didn't adjust the code for v4l2, however with libv4l it should work in linux.. ~Maarten
