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

Josh joshf87 at live.com
Mon Sep 21 07:05:59 CEST 2015


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
>
>
>
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> MPlayer-users at mplayerhq.hu
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>

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.


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