[MPlayer-users] MPEG/DVD crashing when taking screenshot

Roberto Togni rxt at rtogni.it
Thu Sep 24 00:04:37 CEST 2015


On Tue, 22 Sep 2015 00:38:28 -0400
Josh <joshf87 at live.com> wrote:

> On 9/21/2015 16:42, Roberto Togni wrote:
> > On Mon, 21 Sep 2015 01:05:59 -0400
> > Josh <joshf87 at live.com> wrote:
> >
> >> On 9/14/2015 17:40, Roberto Togni wrote:
> >>> On Mon, 14 Sep 2015 20:59:46 +0200
> >>> Roberto Togni <rxt at rtogni.it> wrote:
> >>>
> >>>> On Sun, 13 Sep 2015 00:26:42 -0400
> >>>> Josh <joshf87 at live.com> wrote:
> >>>>
> >>>>> I compiled r37524 with a newer FFmpeg and got different but still
> >>>>> seemingly useless results from gdb so I ran Dr Memory, both logs are
> >>>>> included in the tar.xz. The logs themselves will get me queued for
> >>>>> moderation for being too big:
> >>>>>
> >>>>> http://sourceforge.net/projects/mplayerwin/files/Misc/mpl-bin-r37524-debug-2.tar.xz/download
> >>>>
> >>>> Hi,
> >>>>    just to keep you updated, I was able to reproduce it with your sample
> >>>>    and get a valid backtrace on linux.
> >>>>
> >>>> ...
> >>>> sending VFCTRL_SCREENSHOT!
> >>>>
> >>>> Program received signal SIGSEGV, Segmentation fault.
> >>>> 0x0000555555f68625 in yuv2rgb_X_c_template (hasAlpha=0,
> >>>>       target=AV_PIX_FMT_RGB24, y=13, dstW=2386, dest=0x555558be4680 "",
> >>>>       alpSrc=0x0, chrFilterSize=4, chrVSrc=0x5555572d9a48,
> >>>>       chrUSrc=0x55555711f128, chrFilter=0x5555572d76c8, lumFilterSize=1,
> >>>>       lumSrc=0x55555712c5e8, lumFilter=0x55555711e8ba, c=<optimized out>)
> >>>>       at libswscale/output.c:1340
> >>>> 1340	            Y1 += lumSrc[j][i * 2]     * lumFilter[j];
> >>>> (gdb) bt
> >>>> #0  0x0000555555f68625 in yuv2rgb_X_c_template (hasAlpha=0,
> >>>>       target=AV_PIX_FMT_RGB24, y=13, dstW=2386, dest=0x555558be4680 "",
> >>>>       alpSrc=0x0, chrFilterSize=4, chrVSrc=0x5555572d9a48,
> >>>>       chrUSrc=0x55555711f128, chrFilter=0x5555572d76c8, lumFilterSize=1,
> >>>>       lumSrc=0x55555712c5e8, lumFilter=0x55555711e8ba, c=<optimized out>)
> >>>>       at libswscale/output.c:1340
> >>>> #1  yuv2rgb24_X_c (c=0x555557223520, lumFilter=0x55555711e8ba,
> >>>>       lumSrc=0x55555712c5e8, lumFilterSize=1, chrFilter=0x5555572d76c8,
> >>>>       chrUSrc=0x55555711f128, chrVSrc=0x5555572d9a48, chrFilterSize=4,
> >>>>       alpSrc=0x0, dest=0x555558be4680 "", dstW=2386, y=13)
> >>>>       at libswscale/output.c:1515
> >>>> #2  0x0000555555f4dc9e in packed_vscale (c=<optimized out>,
> >>>>       desc=<optimized out>, sliceY=13, sliceH=<optimized out>)
> >>>>       at libswscale/vscale.c:129
> >>>> #3  0x0000555555f3dc81 in swscale (c=0x5555572b12c0,
> >>>> src=0x55555711e8a0, srcStride=0x1000, srcSliceY=1460470520,
> >>>> srcSliceH=1460470480, dst=0x55555711f128, dstStride=0x7fffffffca80) at
> >>>> libswscale/swscale.c:682 #4  0x0000555555f3ef4b in sws_scale
> >>>> (c=0x5555572b12c0, srcSlice=0x7fffffffca90, srcStride=0x55555712c5e8,
> >>>> srcSliceY=1, srcSliceH=1462597320, dst=0x7fffffffcab0,
> >>>> dstStride=0x5555570f4c60) at libswscale/swscale.c:1263
> >>>> #5  0x00005555558295da in draw_slice (vf=0x5555570f53b0,
> >>>> src=0x7fffffffcb90, stride=0x7fffffffcb80, w=1920, h=16, x=1460791456,
> >>>> y=16)
> >>>>       at libmpcodecs/vf_screenshot.c:64
> >>>> #6  0x0000555555826021 in draw_slice (s=<optimized out>, src=<optimized
> >>>> out>, offset=<optimized out>, y=<optimized out>, type=<optimized out>,
> >>>>       height=<optimized out>) at libmpcodecs/vd_ffmpeg.c:588
> >>>> #7  0x0000555555eb48e4 in ff_draw_horiz_band (avctx=0x5555570f69a0,
> >>>>       cur=<optimized out>, last=<optimized out>, y=16, h=16,
> >>>>       picture_structure=3, first_field=0, low_delay=0)
> >>>>       at libavcodec/mpegutils.c:77
> >>>> #8  0x0000555555b95135 in ff_mpeg_draw_horiz_band
> >>>> (s=s at entry=0x5555570f6e40, y=<optimized out>, h=<optimized out>) at
> >>>> libavcodec/mpegvideo.c:2720 #9  0x0000555555b60db5 in mpeg_decode_slice
> >>>> (s=s at entry=0x5555570f6e40, mb_y=mb_y at entry=1,
> >>>> buf=buf at entry=0x7fffffffcdd8, buf_size=buf_size at entry=2077) at
> >>>> libavcodec/mpeg12dec.c:1927 #10 0x0000555555b63b35 in decode_chunks
> >>>> (avctx=avctx at entry=0x5555570f69a0,
> >>>> picture=picture at entry=0x5555570f6760,
> >>>> got_output=got_output at entry=0x7fffffffcf60, buf=0x555556f088c0 "",
> >>>> buf_size=2111) at libavcodec/mpeg12dec.c:2759 #11 0x0000555555b645ab in
> >>>> mpeg_decode_frame (avctx=0x5555570f69a0, data=0x5555570f6760,
> >>>> got_output=0x7fffffffcf60, avpkt=<optimized out>) at
> >>>> libavcodec/mpeg12dec.c:2836 #12 0x0000555555c6762e in
> >>>> avcodec_decode_video2 (avctx=0x5555570f69a0, picture=0x5555570f6760,
> >>>> got_picture_ptr=0x7fffffffcf60, avpkt=0x7fffffffcf90) at
> >>>> libavcodec/utils.c:2096 ---Type <return> to continue, or q <return> to
> >>>> quit--- #13 0x0000555555826e5f in decode (sh=0x555556edc410,
> >>>> data=0x1000, len=1460848104, flags=-12400) at
> >>>> libmpcodecs/vd_ffmpeg.c:949 #14 0x0000555555775f4f in decode_video
> >>>> (sh_video=0x555556edc410, start=0x555556f088c0 "", in_size=2111,
> >>>> drop_frame=0, pts=1.083922266960144, full_frame=0x7fffffffd0b0)
> >>>>       at libmpcodecs/dec_video.c:398
> >>>> #15 0x00005555556dd772 in update_video (blit_frame=0x7fffffffd158)
> >>>>       at mplayer.c:2484
> >>>> #16 0x00005555556d0980 in main (argc=5, argv=0x7fffffffe288) at
> >>>> mplayer.c:3811
> >>>>
> >>>>
> >>>> You're probably right with the commit that broke it, I'm checking if
> >>>> swscale needs to be called differently now.
> >>>>
> >>>>
> >>> May be a problem in ffmpeg, see https://trac.ffmpeg.org/ticket/4850
> >>>
> >>> I can get a crash with similar backtrace with
> >>> ffmpeg -i mpeg_crash_screenshot.mpg -dsth 1096 -c png -f null /dev/null
> >>>
> >>>
> >>> Program received signal SIGSEGV, Segmentation fault.
> >>> 0x0000000000de5a57 in yuv2rgb_write (hasAlpha=0,
> >>> target=AV_PIX_FMT_RGB24,
> >>>       y=1088, _b=0x1e0f266, _g=0x1e0f266, _r=0x1e0f266, A2=0, A1=0,
> >>>       Y2=<optimized out>, Y1=<optimized out>, i=<optimized out>,
> >>>       _dest=0x7fffcc7f8040 "") at libswscale/output.c:1246
> >>> 1246	        dest[i * 6 + 0] = r_b[Y1];
> >>> (gdb) bt
> >>> #0  0x0000000000de5a57 in yuv2rgb_write (hasAlpha=0,
> >>> target=AV_PIX_FMT_RGB24,
> >>>       y=1088, _b=0x1e0f266, _g=0x1e0f266, _r=0x1e0f266, A2=0, A1=0,
> >>>       Y2=<optimized out>, Y1=<optimized out>, i=<optimized out>,
> >>>       _dest=0x7fffcc7f8040 "") at libswscale/output.c:1246
> >>> #1  yuv2rgb_X_c_template (hasAlpha=0, target=AV_PIX_FMT_RGB24, y=1088,
> >>>       dstW=1920, dest=0x7fffcc7f8040 "", alpSrc=0x0, chrFilterSize=4,
> >>>       chrVSrc=0x1b4dd30, chrUSrc=0x1b44c70, chrFilter=0x1b6e0c0,
> >>>       lumFilterSize=4, lumSrc=0x1b4e4f8, lumFilter=0x1b67440,
> >>> c=<optimized out>)
> >>>       at libswscale/output.c:1370
> >>> #2  yuv2rgb24_X_c (c=0x1ba75c0, lumFilter=0x1b67440, lumSrc=0x1b4e4f8,
> >>>       lumFilterSize=4, chrFilter=0x1b6e0c0, chrUSrc=0x1b44c70,
> >>>       chrVSrc=0x1b4dd30, chrFilterSize=4, alpSrc=0x0, dest=0x7fffcc7f8040
> >>> "",
> >>>       dstW=1920, y=1088) at libswscale/output.c:1515
> >>> #3  0x0000000000dca58e in packed_vscale (c=<optimized out>,
> >>>       desc=<optimized out>, sliceY=1088, sliceH=<optimized out>)
> >>>       at libswscale/vscale.c:129
> >>> #4  0x0000000000dc5d31 in swscale (c=0x1b4e980, src=0x1e0f266,
> >>> srcStride=0x0,
> >>>       srcSliceY=28632888, srcSliceH=28632848, dst=0x1b44c70,
> >>>       dstStride=0x7fffffffd6f0) at libswscale/swscale.c:682
> >>> #5  0x0000000000dc70ba in sws_scale (c=0x1b4e980,
> >>> srcSlice=0x7fffffffd700,
> >>>       srcStride=0x1b4e4f8, srcSliceY=4, srcSliceH=28762304,
> >>> dst=0x7fffffffd720,
> >>>       dstStride=0x7fffffffd7d0) at libswscale/swscale.c:1263
> >>> #6  0x000000000050a088 in scale_slice (y=<optimized out>,
> >>>       link=<optimized out>, field=<optimized out>, mul=<optimized out>,
> >>>       h=<optimized out>, sws=<optimized out>, cur_pic=<optimized out>,
> >>>       out_buf=<optimized out>) at libavfilter/vf_scale.c:477
> >>> #7  filter_frame (link=0x1b44520, in=0x1e0ecc0) at
> >>> libavfilter/vf_scale.c:579
> >>> #8  0x000000000049f1df in ff_filter_frame_framed (link=0x1b44520,
> >>>       frame=0x1e0ecc0) at libavfilter/avfilter.c:1089
> >>> #9  0x00000000004a1299 in ff_filter_frame (link=0x1b44520,
> >>> frame=0x1e0ecc0)
> >>>       at libavfilter/avfilter.c:1173
> >>> #10 0x000000000049f1df in ff_filter_frame_framed (link=0x1b44b20,
> >>>       frame=0x1e0ecc0) at libavfilter/avfilter.c:1089
> >>> #11 0x00000000004a1299 in ff_filter_frame (link=0x1b44b20,
> >>> frame=0x1e0ecc0)
> >>>       at libavfilter/avfilter.c:1173
> >>> #12 0x00000000004a53a2 in request_frame (link=0x1b44b20)
> >>>       at libavfilter/buffersrc.c:378
> >>> #13 0x00000000004a50d4 in av_buffersrc_add_frame_internal (
> >>>       ctx=ctx at entry=0x1b455e0, frame=frame at entry=0x1cca620,
> >>> flags=flags at entry=4)
> >>>       at libavfilter/buffersrc.c:180
> >>> #14 0x00000000004a55cd in av_buffersrc_add_frame_flags (ctx=0x1b455e0,
> >>>       frame=frame at entry=0x1cca620, flags=flags at entry=4)
> >>>       at libavfilter/buffersrc.c:105
> >>> #15 0x0000000000487272 in decode_video (ist=0x1b3ca00, pkt=<optimized
> >>> out>,
> >>>       got_output=<optimized out>) at ffmpeg.c:2179
> >>> #16 0x00000000004715d3 in process_input_packet (pkt=<optimized out>,
> >>>       ist=<optimized out>) at ffmpeg.c:2327
> >>> #17 process_input (file_index=<optimized out>) at ffmpeg.c:3833
> >>> #18 transcode_step () at ffmpeg.c:3921
> >>> #19 transcode () at ffmpeg.c:3974
> >>> #20 main (argc=28559872, argv=0x7fffffffe010) at ffmpeg.c:4157
> >>> (gdb)
> >>>
> >>>
> >>> Seems that the problem is related to slices, in MPlayer it works for the
> >>> first slice but fails for the 2nd (slice height is 16; offset 0 is ok,
> >>> offset 16 crashes).
> >>>
> >>>
> >>> The attached workaroud fixes the crash, but produces a wrong picture;
> >>> unless I missed some stupid detail, it should be equivalent to the old
> >>> code.
> >>>
> >>>
> >>> Ciao,
> >>>    Roberto
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> MPlayer-users mailing list
> >>> MPlayer-users at mplayerhq.hu
> >>> https://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
> >>>
> >>
> >> I compiled the latest MPlayer trunk/FFmpeg master that has a fix for
> >> FFmpeg #4850 and without your patch.
> >>
> >> There is no crash but it simply quits (no screenshot saved) after
> >> 'sending VFCTRL_SCREENSHOT!' when slices are enabled, with the exception
> >> of mpeg_crash_ss_beetlejuice.mpg it quits slices or noslices.
> > Fix for #4850 did not stop the crash for me too.
> >
> > What I found out is that if I force FFmpeg to use the old scaler
> > filters, everything works fine.
> >
> > I was still unable to find out if something changed in the way you need
> > to use swscaler (I don't think so), if there is a bug in the new
> > swscaler, or if we always used it in the wrong way and we were just
> > lucky up to now.
> >
> > I'm not much worried about vf_screenshot, but about all other uses of
> > the scaler code in the mail player.
> >
> > If you want to test it, just comment out #define NEW_FILTER at the end
> > of ffmpeg/libswscale/swscale_internal.h and recompile everything.
> >
> > This is a possible workaround for people using the internal ffmpeg copy
> > of MPlayer, it will not help if you use a system-wide install of ffmpeg.
> >
> >
> > Ciao,
> >   Roberto
> > _______________________________________________
> > MPlayer-users mailing list
> > MPlayer-users at mplayerhq.hu
> > https://lists.mplayerhq.hu/mailman/listinfo/mplayer-users
> >
> 
> As of current FFmpeg master with disabling the new filter everything 
> works fine so far.
I found a way to produce a simple test case that fails in the exact way
as MPlayer.
See ffmpeg ticket https://trac.ffmpeg.org/ticket/4877

Ciao,
 Roberto


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