Crashed when running ffmpeg -filter_complex with multiple instances of libvmaf

[rainliu]

When I ran the following command, it crashed. If there is only one libvmaf instance in -filter_complex, then it works fine.

./ffmpeg4.1/bin/ffmpeg -hide_banner -i encode.mp4 -i bbb_720p1.mp4 -filter_complex "[0:v] split=4 [ref_360][ref_480][ref_720][ref_0]; [1:v] split=4 [enc_360][enc_480][enc_720][enc_0]; [ref_360] scale=-2:360 [ref_360_scaled]; [enc_360][ref_360_scaled] scale2ref=iw:ih [enc_360_scaled][ref_360_scaled]; [ref_360_scaled][enc_360_scaled] libvmaf=./vmaf-model/vmaf_v0.6.1.pkl [out_360]; [ref_480] scale=-2:480 [ref_480_scaled]; [enc_480][ref_480_scaled] scale2ref=iw:ih [enc_480_scaled][ref_480_scaled]; [ref_480_scaled][enc_480_scaled] libvmaf=./vmaf-model/vmaf_v0.6.1.pkl [out_480]; [ref_720] scale=-2:720 [ref_720_scaled]; [enc_720][ref_720_scaled] scale2ref=iw:ih [enc_720_scaled][ref_720_scaled];[ref_720_scaled][enc_720_scaled] libvmaf=./vmaf-model/vmaf_v0.6.1.pkl [out_720]; [ref_0] scale=1280:720 [ref_0_scaled]; [enc_0][ref_0_scaled] scale2ref=iw:ih [enc_0_scaled][ref_0_scaled]; [ref_0_scaled][enc_0_scaled] libvmaf=./vmaf-model/vmaf_v0.6.1.pkl [out_0]" -map "[out_360]" -map "[out_480]" -map "[out_720]" -map "[out_0]" -f null -

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'encode.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
title : 2354886284583946
artist : Blender Foundation 2008, Janus Bager Kristensen 2013
composer : Sacha Goedegebure
encoder : Lavf57.41.100
comment : Creative Commons Attribution 3.0 - http://bbb3d.renderfarming.net
genre : Animation
Duration: 00:02:00.00, start: 0.000000, bitrate: 138 kb/s
Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 256x144 [SAR 1:1 DAR 16:9], 84 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (HE-AAC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 48 kb/s (default)
Metadata:
handler_name : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'bbb_720p1.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
title : Big Buck Bunny, Sunflower version
artist : Blender Foundation 2008, Janus Bager Kristensen 2013
composer : Sacha Goedegebure
encoder : Lavf57.71.100
comment : Creative Commons Attribution 3.0 - http://bbb3d.renderfarming.net
genre : Animation
Duration: 00:02:00.02, start: 0.000000, bitrate: 4627 kb/s
Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 4278 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #1:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 341 kb/s (default)
Metadata:
handler_name : SoundHandler
Stream mapping:
Stream #0:0 (h264) -> fps
Stream #1:0 (h264) -> split
libvmaf -> Stream #0:0 (wrapped_avframe)
libvmaf -> Stream #0:1 (wrapped_avframe)
libvmaf -> Stream #0:2 (wrapped_avframe)
libvmaf -> Stream #0:3 (wrapped_avframe)
Press [q] to stop, [?] for help
Start calculating VMAF score...
Start calculating VMAF score...
*** Error in `./ffmpeg4/bin/ffmpeg_bin': free(): invalid next size (normal): 0x00007fec580082a0 ***
Start calculating VMAF score...
======= Backtrace: =========
/usr/local/gcc-5-glibc-2.23/lib/libc.so.6(+0x7a786)[0x7fed0ee3b786]
/usr/local/gcc-5-glibc-2.23/lib/libc.so.6(+0x833f7)[0x7fed0ee443f7]
/usr/local/gcc-5-glibc-2.23/lib/libc.so.6(cfree+0x51)[0x7fed0ee48151]
/usr/local/ffmpeg4/bin/libvmaf.so(svm_load_model+0x329)[0x7fed0eaad669]
/usr/local/ffmpeg4/bin/libvmaf.so(_ZN25LibsvmNusvrTrainTestModel26_read_and_assert_svm_modelEPKc+0x18)[0x7fed0eab07c8]
/usr/local/ffmpeg4/bin/libvmaf.so(_ZN25LibsvmNusvrTrainTestModel10load_modelEv+0x170)[0x7fed0eab55e0]
/usr/local/ffmpeg4/bin/libvmaf.so(_ZN17VmafQualityRunner11_load_modelEPKc+0xbd)[0x7fed0eab57ad]
/usr/local/ffmpeg4/bin/libvmaf.so(_ZN17VmafQualityRunner3runE5AssetPFiPfS1_S1_iPvES2_bbbbbii+0x74)[0x7fed0eab6a64]
/usr/local/ffmpeg4/bin/libvmaf.so(_Z7RunVmafPKciiPFiPfS1_S1_iPvES2_S0_S0_S0_bbbbbS0_iib+0x18b)[0x7fed0eab91eb]
/usr/local/ffmpeg4/bin/libvmaf.so(compute_vmaf+0xc0)[0x7fed0eafc8d0]
/usr/local/ffmpeg4/bin/libavfilter.so.7(+0x1693bc)[0x7fed11c0e3bc]
/usr/local/gcc-5-glibc-2.23/lib/libpthread.so.0(+0x77c9)[0x7fed0f1957c9]
/usr/local/gcc-5-glibc-2.23/lib/libc.so.6(clone+0x6d)[0x7fed0eecebad]
======= Memory map: ========
00400000-0043e000 r-xp 00000000 00:1a 249339990 /usr/local/ffmpeg4-trunk/bin/ffmpeg_bin
0063d000-00641000 rw-p 0003d000 00:1a 249339990 /usr/local/ffmpeg4-trunk/bin/ffmpeg_bin