scpr: crash with 16bpp

[ami_stuff]

decodes correctly with original codec

(gdb) r -i '/media/sdb1/f/sp/sp_16bit_q100_o.avi'  -f null -
Starting program: /media/sdb1/ffmpeg/ffmpeg_g -i '/media/sdb1/f/sp/sp_16bit_q100_o.avi'  -f null -
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/i386-linux-gnu/libthread_db.so.1".
ffmpeg version 3.2.git Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 5.3.0 (Ubuntu 5.3.0-3ubuntu1~14.04) 20151204
  configuration: --disable-ffprobe --disable-ffserver --disable-ffplay --enable-gpl
  libavutil      55. 47.100 / 55. 47.100
  libavcodec     57. 81.100 / 57. 81.100
  libavformat    57. 66.102 / 57. 66.102
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 73.100 /  6. 73.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
  libpostproc    54.  2.100 / 54.  2.100
Input #0, avi, from '/media/sdb1/f/sp/sp_16bit_q100_o.avi':
  Metadata:
    encoder         : Lavf57.36.100
  Duration: 00:00:04.44, start: 0.000000, bitrate: 727 kb/s
    Stream #0:0: Video: scpr (SCPR / 0x52504353), rgb0, 318x198, 714 kb/s, 25 fps, 25 tbr, 25 tbn, 25 tbc
[New Thread 0xb68c6b40 (LWP 14539)]
[New Thread 0xb60c5b40 (LWP 14540)]
[New Thread 0xb58c4b40 (LWP 14541)]
[New Thread 0xb50c3b40 (LWP 14542)]
[New Thread 0xb48c2b40 (LWP 14543)]
[New Thread 0xb40c1b40 (LWP 14544)]
[New Thread 0xb38c0b40 (LWP 14545)]
[New Thread 0xb30bfb40 (LWP 14546)]
[New Thread 0xb28beb40 (LWP 14547)]
Output #0, null, to 'pipe:':
  Metadata:
    encoder         : Lavf57.66.102
    Stream #0:0: Video: wrapped_avframe, rgb0, 318x198, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
    Metadata:
      encoder         : Lavc57.81.100 wrapped_avframe
Stream mapping:
  Stream #0:0 -> #0:0 (scpr (native) -> wrapped_avframe (native))
Press [q] to stop, [?] for help

Program received signal SIGSEGV, Segmentation fault.
decode_unit (s=s@entry=0xb68c7020, pixel=pixel@entry=0xb76a08c8, 
    rval=rval@entry=0xbfffe710, step=400) at libavcodec/scpr.c:224
224	    pixel->freq[c] = cnt_c + step;
(gdb) bt
#0  decode_unit (s=s@entry=0xb68c7020, pixel=pixel@entry=0xb76a08c8, 
    rval=rval@entry=0xbfffe710, step=400) at libavcodec/scpr.c:224
#1  0x086add77 in decompress_i (linesize=320, dst=0xb2042020, avctx=0x9a29ca0)
    at libavcodec/scpr.c:307
#2  decode_frame (avctx=0x9a29ca0, data=0x9a2bf20, got_frame=0xbfffe81c, 
    avpkt=0xbfffe78c) at libavcodec/scpr.c:686
#3  0x08729a59 in avcodec_decode_video2 (avctx=0x9a29ca0, picture=0x9a2bf20, 
    got_picture_ptr=0xbfffe81c, avpkt=0xbfffe918) at libavcodec/utils.c:2263
#4  0x0872a9dd in do_decode (avctx=avctx@entry=0x9a29ca0, 
    pkt=pkt@entry=0xbfffe918) at libavcodec/utils.c:2796
#5  0x0872b7b0 in avcodec_send_packet (avctx=0x9a29ca0, avpkt=<optimized out>)
    at libavcodec/utils.c:2885
#6  0x080e8447 in decode (pkt=0xbfffe918, got_frame=0xbfffeab4, 
    frame=<optimized out>, avctx=0x9a29ca0) at ffmpeg.c:2052
#7  decode_video (ist=ist@entry=0x9a29940, pkt=pkt@entry=0xbfffeaf4, 
    got_output=got_output@entry=0xbfffeab4, eof=0) at ffmpeg.c:2248
#8  0x080e9806 in process_input_packet (ist=0x9a29940, pkt=0xbfffed24, 
    no_eof=0) at ffmpeg.c:2491
#9  0x080c78d6 in process_input (file_index=<optimized out>) at ffmpeg.c:4251
#10 transcode_step () at ffmpeg.c:4339
#11 transcode () at ffmpeg.c:4393
#12 main (argc=<optimized out>, argv=<optimized out>) at ffmpeg.c:4598
(gdb) 

[richardpl]

This decodes to green nonsense. What you used to encode this?

[ami_stuff]

Replying to richardpl:

This decodes to green nonsense.

It decodes here just fine with 32bit codec.

What you used to encode this?

VirtualDub? + original codec.

[richardpl]

What version of "original codec"?

[richardpl]

Also send picture of one decoded frame.

[ami_stuff]

​http://www.infognition.com/ScreenPressor/download.html

The original codec is buggy as well because it crashes with attached new files (when quality is lower than 72), so yes fixing the crash should be probably enough.

[richardpl]

Fixed in fd7af82c53ea8a2577ea8952d35fb158db594592.

[ami_stuff]

It looks like for certain resolutions this codec is encoding video in lossy compression mode even if not asked to do so?