Segmentation fault when applying the "--no-wpp"

[bujyu]

I met the problem that when i applying the option "--no-wpp" and preset was ultrafast, superfast or veryfast,

the execution would crash and display "Segmentation fault", I didn't meet this problem in version 1.4+222-5f9f7194267b.

The log of info as follow ( preset was ultrafast ) :

$ x265 --input ./sequence/BasketballDrive_1920x1080_50.yuv --output ./Basketball.x265 -input-res 1920x1080 --fps 50 --preset ultrafast --no-wpp

yuv [info]: 1920x1080 fps 50000/1000 i420p8 frames 0 - 500 of 501

x265 [info]: HEVC encoder version 1.5+219-db86567c3f5c

x265 [info]: build info [Linux][GCC 4.8.2][64 bit] 8bpp

x265 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX

x265 [info]: Main profile, Level-4.1 (Main tier)

x265 [info]: frame threads / pool features : 17 / none

Segmentation fault

[Deepthi Nandakumar]

Thanks - can you check the commits right after this revision? We found and fixed this just today :)

[bujyu]

I update to version 1.5+221-b931c50d5501,

but it was still crash and display "Segmentation fault"...

[Deepthi Nandakumar]

What machine are you running this on? 17 is very high for frame threads.

[bujyu]

Dual Intel Xeon E5-2670 v2, and I had test on different machine which has dual Intel Xeon E5-2620

[Deepthi Nandakumar]

Thanks, we have X265_MAX_FRAME_THREADS set to 16. And if you aren't setting this from the commandline, can you step through and see what causes 17 frame threads to be printed (if not created)?

[Deepthi Nandakumar]

Great, I can reproduce this on E5-2690, checking now.

[bujyu]

Like this? "DEBUG OUPUT" is to monitor the variable in encoder/encoder.cpp

$ x265 --input ./sequence/BasketballDrive_1920x1080_50.yuv --output ./Basketball.x265 --input-res 1920x1080 --fps 50 --preset ultrafast --no-wpp

yuv [info]: 1920x1080 fps 50000/1000 i420p8 frames 0 - 500 of 501

x265 [info]: HEVC encoder version 1.5+221-b931c50d5501

x265 [info]: build info [Linux][GCC 4.4.7][64 bit] 8bpp

x265 [info]: using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX

x265 [info]: Main profile, Level-4.1 (Main tier)

DEBUG OUTPUT encoder.cpp:112 : frame thread = 0

DEBUG OUTPUT encoder.cpp:118 : CPU count = 40

DEBUG OUTPUT encoder.cpp:119 : rows = 34

DEBUG OUTPUT encoder.cpp:134 : frame thread = 17

x265 [info]: frame threads / pool features : 17 / none

Segmentation fault (core dumped)

[bujyu]

I think the problem is caused by the size of m_frameEncoder.

In version 1.4+222-5f9f7194267b, the m_frameEncoder allocated at encoder.cpp and the size was m_param->frameNumThreads.

But in version 1.5+219-db86567c3f5c, the m_frameEncoder allocated at encoder.h and the size was X265_MAX_FRAME_THREADS ( it defined at x265.h and was 16 )

So, if any loop condition was "0 < m_param->frameNumThreads".

the index would be out of range and caused the Segment fault

[Deepthi Nandakumar]

Thanks, fix pushed.

[bujyu]

Thanks, it can work now.