[FFmpeg-devel] [PATCH 1/2] avcodec/apedec: Fix CRC for 24bps and bigendian

[Michael Niedermayer <michael@niedermayer.cc>]

Fixes CRC for vlc.ape and APE_48K_24bit_2CH_02_01.ape

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
---
 libavcodec/apedec.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
index 613c76df0b..7bad8500e1 100644
--- a/libavcodec/apedec.c
+++ b/libavcodec/apedec.c
@@ -1625,13 +1625,24 @@ static int ape_decode_frame(AVCodecContext *avctx, AVFrame *frame,
     s->samples -= blockstodecode;
 
     if (avctx->err_recognition & AV_EF_CRCCHECK &&
-        s->fileversion >= 3900 && s->bps < 24) {
+        s->fileversion >= 3900) {
         uint32_t crc = s->CRC_state;
         const AVCRC *crc_tab = av_crc_get_table(AV_CRC_32_IEEE_LE);
+        int stride = s->bps == 24 ? 4 : (s->bps>>3);
+        int offset = s->bps == 24;
+        int bytes  = s->bps >> 3;
+
         for (i = 0; i < blockstodecode; i++) {
             for (ch = 0; ch < s->channels; ch++) {
-                uint8_t *smp = frame->data[ch] + (i*(s->bps >> 3));
-                crc = av_crc(crc_tab, crc, smp, s->bps >> 3);
+#if HAVE_BIGENDIAN
+                uint8_t *smp_native = frame->data[ch] + i*stride;
+                uint8_t smp[4];
+                for(int j = 0; j<stride; j++)
+                    smp[j] = smp_native[stride-j-1];
+#else
+                uint8_t *smp = frame->data[ch] + i*stride;
+#endif
+                crc = av_crc(crc_tab, crc, smp+offset, bytes);
             }
         }
 
-- 
2.17.1

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