Multi-threaded decoding error in ver2.4.1

[y9o]

Hello,

It seems that setting DECODER_OPTION_NUM_OF_THREADS to 2 or higher leads to hang-ups. This issue is not present in older versions.

Symptoms similar to issue #3487.

h264dec.cpp:

  int32_t iThreadCount = 3;
  pDecoder->SetOption (DECODER_OPTION_NUM_OF_THREADS, &iThreadCount);

Hang-ups observed:

openh264-2.4.1$ wget https://test-videos.co.uk/vids/bigbuckbunny/mp4/h264/1080/Big_Buck_Bunny_1080_10s_30MB.mp4
openh264-2.4.1$ ffmpeg -i Big_Buck_Bunny_1080_10s_30MB.mp4 -map 0:0 -vcodec copy -an Big_Buck_Bunny_1080_10s_30MB.264
openh264-2.4.1$ make -j BUILDTYPE=Release USE_ASM=No HAVE_AVX2=No
openh264-2.4.1$ ./h264dec Big_Buck_Bunny_1080_10s_30MB.264 x.yuv  -trace 8
[OpenH264] this = 0x0x56518f677ee0, Info:CWelsDecoder::init_decoder(), openh264 codec version = , ParseOnly = 0
[OpenH264] this = 0x0x56518f677ee0, Info:CWelsDecoder::init_decoder(), openh264 codec version = , ParseOnly = 0
[OpenH264] this = 0x0x56518f677ee0, Info:eVideoType: 1
[OpenH264] this = 0x0x56518f677ee0, Info:CWelsDecoder::init_decoder(), openh264 codec version = , ParseOnly = 0
[OpenH264] this = 0x0x56518f677ee0, Info:eVideoType: 1
[OpenH264] this = 0x0x56518f677ee0, Info:CWelsDecoder::init_decoder(), openh264 codec version = , ParseOnly = 0
[OpenH264] this = 0x0x56518f677ee0, Info:eVideoType: 1
[OpenH264] this = 0x0x56518f677ee0, Info:CWelsDecoder::SetOption for ERROR_CON_IDC = 2.
H264 source file name: Big_Buck_Bunny_1080_10s_30MB.264..
Sequence output file name: x.yuv..
------------------------------------------------------
[OpenH264] this = 0x0x56518f677ee0, Info:WelsRequestMem(): memory alloc size = 1920 * 1088, ref list size = 20
[OpenH264] this = 0x0x56518f677ee0, Info:SyncPictureResolutionExt(), overall memory usage: 116230782 bytes
[OpenH264] this = 0x0x56518f677ee0, Info:DecodeFrameConstruction(): will output first frame of new sequence, 1920 x 1088, crop_left:0, crop_right:0, crop_top:0, crop_bottom:4, ignored error packet:0.
[OpenH264] this = 0x0x56518f677ee0, Error:DecodeCurrentAccessUnit()::::::PrefetchPic ERROR, pSps->iNumRefFrames:16.
[OpenH264] this = 0x0x56518f677ee0, Debug:returned error from decoding:[0x3f2]
[OpenH264] this = 0x0x56518f677ee0, Info:ResetDecoder(), context error code is 16384

Thank you.

[tyan0]

Hi,

This seems due to my commit 0a6d2d8 via #3707.
I would like to create another PR to fix that. Sorry for my mistake.