libavcodec/alsdec.c:1400: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `revert_channel_correlation`.

libavcodec/alsdec.c:1375:9: Call
1373.         bd.prev_raw_samples = ctx->prev_raw_samples;
1374. 
1375.         get_block_sizes(ctx, div_blocks, &bs_info);
              ^
1376. 
1377.         for (b = 0; b < ctx->num_blocks; b++) {

libavcodec/alsdec.c:499:1: Parameter `ctx->sconf.frame_length`
  497.  *  actual number of samples.
  498.  */
  499. static void get_block_sizes(ALSDecContext *ctx, unsigned int *div_blocks,
       ^
  500.                             uint32_t *bs_info)
  501. {

libavcodec/alsdec.c:532:9: Assignment
  530. 
  531.     for (b = 0; b < ctx->num_blocks; b++)
  532.         div_blocks[b] = ctx->sconf.frame_length >> div_blocks[b];
               ^
  533. 
  534.     if (ctx->cur_frame_length != ctx->sconf.frame_length) {

libavcodec/alsdec.c:1378:13: Assignment
1376. 
1377.         for (b = 0; b < ctx->num_blocks; b++) {
1378.             bd.block_length = div_blocks[b];
                  ^
1379. 
1380.             for (c = 0; c < avctx->channels; c++) {

libavcodec/alsdec.c:1400:23: Call
1398. 
1399.             for (c = 0; c < avctx->channels; c++) {
1400.                 ret = revert_channel_correlation(ctx, &bd, ctx->chan_data,
                            ^
1401.                                                  reverted_channels, offset, c);
1402.                 if (ret < 0)

libavcodec/alsdec.c:1215:1: <LHS trace>
1213. /** Recursively reverts the inter-channel correlation for a block.
1214.  */
1215. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
      ^
1216.                                        ALSChannelData **cd, int *reverted,
1217.                                        unsigned int offset, int c)

libavcodec/alsdec.c:1215:1: Parameter `bd->block_length`
  1213. /** Recursively reverts the inter-channel correlation for a block.
  1214.  */
  1215. static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
        ^
  1216.                                        ALSChannelData **cd, int *reverted,
  1217.                                        unsigned int offset, int c)

libavcodec/alsdec.c:1255:9: Binary operation: ([0, +oo] - 1):unsigned32 by call to `revert_channel_correlation` 
  1253.         unsigned int smp;
  1254.         unsigned int begin = 1;
  1255.         unsigned int end   = bd->block_length - 1;
                ^
  1256.         int64_t y;
  1257.         int32_t *master = ctx->raw_samples[ch[dep].master_channel] + offset;
