adpcm_swf: Use correct sample offsets when using trellis.

Fixes invalid reads when encoding mono streams when trellis is used.
12 years ago · 5d4ef004bf
parent 7011a42b1a
commit 5d4ef004bf
1 changed files with 4 additions and 3 deletions
--- a/libavcodec/adpcmenc.c
+++ b/libavcodec/adpcmenc.c
@ -615,10 +615,11 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,

        if (avctx->trellis > 0) {
            FF_ALLOC_OR_GOTO(avctx, buf, 2 * n, error);
-            adpcm_compress_trellis(avctx, samples + 2, buf, &c->status[0], n);
+            adpcm_compress_trellis(avctx, samples + avctx->channels, buf,
+                                   &c->status[0], n);
            if (avctx->channels == 2)
-                adpcm_compress_trellis(avctx, samples + 3, buf + n,
-                                       &c->status[1], n);
+                adpcm_compress_trellis(avctx, samples + avctx->channels + 1,
+                                       buf + n, &c->status[1], n);
            for (i = 0; i < n; i++) {
                put_bits(&pb, 4, buf[i]);
                if (avctx->channels == 2)