[FFmpeg-devel] [PATCH] avcodec/alsdec: relax opt_order limit

[Michael Niedermayer]

Fixes: Ticket5297

Needs review by maintainer / author to check that this is ok and sufficient
---
 libavcodec/alsdec.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libavcodec/alsdec.c b/libavcodec/alsdec.c
index a7e58a2..9410f52 100644
--- a/libavcodec/alsdec.c
+++ b/libavcodec/alsdec.c
@@ -694,7 +694,7 @@ static int read_var_block_data(ALSDecContext *ctx, ALSBlockData *bd)
         } else {
             *bd->opt_order = sconf->max_order;
         }
-        if (*bd->opt_order > bd->block_length) {
+        if (*bd->opt_order > bd->block_length + sconf->max_order) {
             *bd->opt_order = bd->block_length;
             av_log(avctx, AV_LOG_ERROR, "Predictor order too large.\n");
             return AVERROR_INVALIDDATA;
@@ -1252,7 +1252,7 @@ static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
     ALSChannelData *ch = cd[c];
     unsigned int   dep = 0;
     unsigned int channels = ctx->avctx->channels;
-    unsigned int channel_size = ctx->sconf.frame_length + ctx->sconf.max_order;
+    unsigned int channel_size = ctx->sconf.frame_length + 2*ctx->sconf.max_order;
 
     if (reverted[c])
         return 0;
@@ -1311,7 +1311,7 @@ static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
             }
 
             if (FFMIN(begin - 1, begin - 1 + t) < ctx->raw_buffer - master ||
-                FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master) {
+                FFMAX(end   + 1,   end + 1 + t) > ctx->raw_buffer + channels * channel_size - master - ctx->sconf.max_order) {
                 av_log(ctx->avctx, AV_LOG_ERROR,
                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",
                        master + FFMIN(begin - 1, begin - 1 + t), master + FFMAX(end + 1,   end + 1 + t),
@@ -1333,7 +1333,7 @@ static int revert_channel_correlation(ALSDecContext *ctx, ALSBlockData *bd,
         } else {
 
             if (begin - 1 < ctx->raw_buffer - master ||
-                end   + 1 > ctx->raw_buffer + channels * channel_size - master) {
+                end   + 1 > ctx->raw_buffer + channels * channel_size - master - ctx->sconf.max_order) {
                 av_log(ctx->avctx, AV_LOG_ERROR,
                        "sample pointer range [%p, %p] not contained in raw_buffer [%p, %p].\n",
                        master + begin - 1, master + end + 1,
@@ -1797,7 +1797,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
         ctx->reverted_channels = NULL;
     }
 
-    channel_size      = sconf->frame_length + sconf->max_order;
+    channel_size      = sconf->frame_length + 2*sconf->max_order;
 
     ctx->prev_raw_samples = av_malloc_array(sconf->max_order, sizeof(*ctx->prev_raw_samples));
     ctx->raw_buffer       = av_mallocz_array(avctx->channels * channel_size, sizeof(*ctx->raw_buffer));
-- 
1.7.9.5