atrac3: Fix crash in tonal component decoding.
Fixes Ticket780
Bug Found by: cosminamironesei

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 9af6abdc17deb95c9b1f1d9242ba49b8b5e0b016)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
diff --git a/libavcodec/atrac3.c b/libavcodec/atrac3.c
index 81d25ec..22dfdfc 100644
--- a/libavcodec/atrac3.c
+++ b/libavcodec/atrac3.c
@@ -454,6 +454,8 @@
 
             for (k=0; k<coded_components; k++) {
                 sfIndx = get_bits(gb,6);
+                if(component_count>=64)
+                    return AVERROR_INVALIDDATA;
                 pComponent[component_count].pos = j * 64 + (get_bits(gb,6));
                 max_coded_values = 1024 - pComponent[component_count].pos;
                 coded_values = coded_values_per_component + 1;