encoding mono audio with opus codec segfaults

[James Cowgill]

Attempting to encode any mono audio with the opus codec (any mux) causes ffmpeg to segfault. This is a regression in 3.4 (3.3 works).

gdb --args ./ffmpeg_g -f lavfi -i sine=d=0.1 -strict -2 -c:a opus -f null /dev/null
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Reading symbols from ./ffmpeg_g...done.
(gdb) r
Starting program: /home/jcowgill/deb-pkg/ffmpeg/upstream/ffmpeg_g -f lavfi -i sine=d=0.1 -strict -2 -c:a opus -f null /dev/null
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
ffmpeg version N-87950-g53eea3a569 Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 7 (Debian 7.2.0-11)
  configuration: --disable-doc --disable-optimizations --enable-debug --disable-autodetect
  libavutil      55. 79.100 / 55. 79.100
  libavcodec     57.108.101 / 57.108.101
  libavformat    57. 84.101 / 57. 84.101
  libavdevice    57. 11.101 / 57. 11.101
  libavfilter     6.108.100 /  6.108.100
  libswscale      4.  9.100 /  4.  9.100
  libswresample   2. 10.100 /  2. 10.100
[New Thread 0x7ffff6e01700 (LWP 25127)]
[New Thread 0x7ffff6600700 (LWP 25128)]
[New Thread 0x7ffff5dff700 (LWP 25129)]
[New Thread 0x7ffff55fe700 (LWP 25130)]
Input #0, lavfi, from 'sine=d=0.1':
  Duration: N/A, start: 0.000000, bitrate: 705 kb/s
    Stream #0:0: Audio: pcm_s16le, 44100 Hz, mono, s16, 705 kb/s
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> opus (native))
Press [q] to stop, [?] for help
[New Thread 0x7ffff4dfd700 (LWP 25131)]
[New Thread 0x7ffff45fc700 (LWP 25132)]
[New Thread 0x7ffff3dfb700 (LWP 25133)]
[New Thread 0x7ffff35fa700 (LWP 25134)]
Output #0, null, to '/dev/null':
  Metadata:
    encoder         : Lavf57.84.101
    Stream #0:0: Audio: opus, 48000 Hz, mono, fltp, 48 kb/s
    Metadata:
      encoder         : Lavc57.108.101 opus
[Parsed_sine_0 @ 0x55555772de20] EOF timestamp not reliable

Thread 1 "ffmpeg_g" received signal SIGSEGV, Segmentation fault.
0x000055555652c855 in pvq_band_cost (pvq=0x555557770660, f=0x7ffff7e24040, rc=0x7fffffffd160, band=0, bits=0x7fffffffd15c, lambda=1)
    at libavcodec/opus_pvq.c:928
928	        err_y += (Y[i] - Y_orig[i])*(Y[i] - Y_orig[i]);
(gdb) p Y
$1 = (float *) 0x0
(gdb) bt
#0  0x000055555652c855 in pvq_band_cost (pvq=0x555557770660, f=0x7ffff7e24040, rc=0x7fffffffd160, band=0, bits=0x7fffffffd15c, lambda=1)
    at libavcodec/opus_pvq.c:928
#1  0x0000555555dc7c42 in bands_dist (s=0x555557742e40, f=0x7ffff7e24040, total_dist=0x7fffffffd70c) at libavcodec/opusenc_psy.c:323
#2  0x0000555555dc7d85 in celt_search_for_intensity (s=0x555557742e40, f=0x7ffff7e24040) at libavcodec/opusenc_psy.c:354
#3  0x0000555555dc82b6 in ff_opus_psy_celt_frame_process (s=0x555557742e40, f=0x7ffff7e24040, index=0) at libavcodec/opusenc_psy.c:408
#4  0x0000555555dc3b3b in celt_encode_frame (s=0x555557742e20, rc=0x5555578cc780, f=0x7ffff7e24040, index=0) at libavcodec/opusenc.c:869
#5  0x0000555555dc421b in opus_encode_frame (avctx=0x555557742940, avpkt=0x55555774c180, frame=0x0, got_packet_ptr=0x7fffffffd9ac)
    at libavcodec/opusenc.c:997
#6  0x0000555555b297c8 in avcodec_encode_audio2 (avctx=0x555557742940, avpkt=0x55555774c180, frame=0x0, got_packet_ptr=0x7fffffffd9ac)
    at libavcodec/encode.c:198
#7  0x0000555555b2a312 in do_encode (avctx=0x555557742940, frame=0x0, got_packet=0x7fffffffd9ac) at libavcodec/encode.c:381
#8  0x0000555555b2a4be in avcodec_send_frame (avctx=0x555557742940, frame=0x0) at libavcodec/encode.c:427
#9  0x0000555555636b74 in flush_encoders () at fftools/ffmpeg.c:1931
#10 0x0000555555640d80 in transcode () at fftools/ffmpeg.c:4647
#11 0x0000555555641447 in main (argc=12, argv=0x7fffffffe0f8) at fftools/ffmpeg.c:4830

[colin ng]

It still crashes with the commit "6e0723470bea258ceb72ee4c4916cf8f80337f92" which is supposed to fix the issue.

It crashes at ff_pvq_search_exact_avx () with the above commit.

[colin ng]

It still crashes with the commit "6e0723470bea258ceb72ee4c4916cf8f80337f92" which is supposed to fix the issue.

It crashes at ff_pvq_search_exact_avx () with the above commit.

[Carl Eugen Hoyos]

Swiftly fixed by Rostislav in f141b353e60f1081185927a1e74a9ab46cae8bef