libavcodec/alsdec.c:1245: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `revert_channel_correlation`.

libavcodec/alsdec.c:1224:9: Call
1222.         bd.prev_raw_samples = ctx->prev_raw_samples;
1223. 
1224.         get_block_sizes(ctx, div_blocks, &bs_info);
              ^
1225. 
1226.         for (b = 0; b < ctx->num_blocks; b++) {

libavcodec/alsdec.c:461:1: Parameter `ctx->sconf.frame_length`
  459.  *  actual number of samples.
  460.  */
  461. static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
       ^
  462.                             uint32_t *bs_info)
  463. {

libavcodec/alsdec.c:494:9: Assignment
  492. 
  493.     for (b = 0; b < ctx->num_blocks; b++)
  494.         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
               ^
  495. 
  496.     if (ctx->cur_frame_length != ctx->sconf.frame_length) {

libavcodec/alsdec.c:1228:13: Assignment
1226.         for (b = 0; b < ctx->num_blocks; b++) {
1227.             bd.shift_lsbs   = 0;
1228.             bd.block_length = div_blocks[b];
                  ^
1229. 
1230.             for (c = 0; c < avctx->channels; c++) {

libavcodec/alsdec.c:1245:21: Call
1243. 
1244.             for (c = 0; c < avctx->channels; c++)
1245.                 if (revert_channel_correlation(ctx, &bd, ctx->chan_data,
                          ^
1246.                                                reverted_channels, offset, c))
1247.                     return -1;

libavcodec/alsdec.c:1069:1: <LHS trace>
1067. /** Recursively reverts the inter-channel correlation for a block.
1068.  */
1069. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
      ^
1070.                                        ALSChannelData **cd, int *reverted,
1071.                                        unsigned int offset, int c)

libavcodec/alsdec.c:1069:1: Parameter `bd->block_length`
  1067. /** Recursively reverts the inter-channel correlation for a block.
  1068.  */
  1069. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
        ^
  1070.                                        ALSChannelData **cd, int *reverted,
  1071.                                        unsigned int offset, int c)

libavcodec/alsdec.c:1105:9: Binary operation: ([0, +oo] - 1):unsigned32 by call to `revert_channel_correlation` 
  1103.         unsigned int smp;
  1104.         unsigned int begin = 1;
  1105.         unsigned int end   = bd->block_length - 1;
                ^
  1106.         int64_t y;
  1107.         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
