ffmpeg patch to patch 42 to avoid infinite loop

third_party/ffmpeg/patched-ffmpeg-mt/libavcodec/aac.c

 /*
  * AAC decoder
  * Copyright (c) 2005-2006 Oded Shimon ( ods15 ods15 dyndns org )
  * Copyright (c) 2006-2007 Maxim Gavrilov ( maxim.gavrilov gmail com )
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
@@ skipping 623 matching lines @@
             uint8_t sect_len = k;
             int sect_len_incr;
             int sect_band_type = get_bits(gb, 4);
             if (sect_band_type == 12) {
                 av_log(ac->avccontext, AV_LOG_ERROR, "invalid band type\n");
                 return -1;
             }
             while ((sect_len_incr = get_bits(gb, bits)) == (1 << bits)-1)
                 sect_len += sect_len_incr;
             sect_len += sect_len_incr;
-            if (sect_len > ics->max_sfb || sect_len == 0) {
+            if (sect_len > ics->max_sfb || sect_len == k) {
                 av_log(ac->avccontext, AV_LOG_ERROR,
                     "Number of bands (%d) is invalid, limit (%d).\n",
                     sect_len, ics->max_sfb);
                 return -1;
             }
             for (; k < sect_len; k++) {
                 band_type        [idx]   = sect_band_type;
                 band_type_run_end[idx++] = sect_len;
             }
         }
@@ skipping 1077 matching lines @@
     CODEC_TYPE_AUDIO,
     CODEC_ID_AAC,
     sizeof(AACContext),
     aac_decode_init,
     NULL,
     aac_decode_close,
     aac_decode_frame,
     .long_name = NULL_IF_CONFIG_SMALL("Advanced Audio Coding"),
     .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
 };