[FFmpeg-devel] [PATCH 2/2] avformat/framecrcenc: Make side-data checksums endian-independent

[Andreas Rheinhardt]

Do this by converting big-endian side data to little endian for
checksumming. Fixes the ts-demux FATE test.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
a) When commenting the #if HAVE_BIGENDIAN out, I get the same checksum
for the test in [1] as Andriy got on a real BE system; I have not done
more testing, lacking actual BE hardware. In particular, the claim about
the ts-demux FATE test is untested.
b) If side data doesn't have the expected size, then LE and BE might
still produce different results (but then there must be a bigger problem
elsewhere).
c) This code here is designed to work even after the next major version
bump when the size of some members of AVCPBProperties change. (Of course,
some FATE checksums will need to be adapted then, but for both LE and BE
in the same manner.)

 libavformat/framecrcenc.c | 61 +++++++++++++++++++++++++++++++++++----
 1 file changed, 56 insertions(+), 5 deletions(-)

diff --git a/libavformat/framecrcenc.c b/libavformat/framecrcenc.c
index f7c48779a0..390024dbe8 100644
--- a/libavformat/framecrcenc.c
+++ b/libavformat/framecrcenc.c
@@ -21,9 +21,11 @@
 
 #include <inttypes.h>
 
+#include "config.h"
 #include "libavutil/adler32.h"
 #include "libavutil/avstring.h"
 #include "libavutil/intreadwrite.h"
+#include "libavcodec/avcodec.h"
 #include "avformat.h"
 #include "internal.h"
 
@@ -43,6 +45,19 @@ static int framecrc_write_header(struct AVFormatContext *s)
     return ff_framehash_write_header(s);
 }
 
+#if HAVE_BIGENDIAN
+static void inline bswap(char *buf, int offset, int size)
+{
+    if (size == 8) {
+        uint64_t val = AV_RN64(buf + offset);
+        AV_WN64(buf + offset, av_bswap64(val));
+    } else if (size == 4) {
+        uint32_t val = AV_RN32(buf + offset);
+        AV_WN32(buf + offset, av_bswap32(val));
+    }
+}
+#endif
+
 static int framecrc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
 {
     uint32_t crc = av_adler32_update(0, pkt->data, pkt->size);
@@ -58,17 +73,53 @@ static int framecrc_write_packet(struct AVFormatContext *s, AVPacket *pkt)
 
         for (i=0; i<pkt->side_data_elems; i++) {
             const AVPacketSideData *const sd = &pkt->side_data[i];
+            const uint8_t *data = sd->data;
             uint32_t side_data_crc = 0;
-            if (HAVE_BIGENDIAN && AV_PKT_DATA_PALETTE == pkt->side_data[i].type) {
+
+            switch (sd->type) {
+#if HAVE_BIGENDIAN
+                uint8_t buf[FFMAX(sizeof(AVCPBProperties),
+                                  sizeof(AVProducerReferenceTime))];
+            case AV_PKT_DATA_PALETTE:
+            case AV_PKT_DATA_REPLAYGAIN:
+            case AV_PKT_DATA_DISPLAYMATRIX:
+            case AV_PKT_DATA_STEREO3D:
+            case AV_PKT_DATA_AUDIO_SERVICE_TYPE:
+            case AV_PKT_DATA_FALLBACK_TRACK:
+            case AV_PKT_DATA_MASTERING_DISPLAY_METADATA:
+            case AV_PKT_DATA_SPHERICAL:
+            case AV_PKT_DATA_CONTENT_LIGHT_LEVEL:
+            case AV_PKT_DATA_S12M_TIMECODE:
                 for (int j = 0; j < sd->size / 4; j++) {
                     uint8_t buf[4];
                     AV_WL32(buf, AV_RB32(sd->data + 4 * j));
                     side_data_crc = av_adler32_update(side_data_crc, buf, 4);
                 }
-            } else {
-                side_data_crc = av_adler32_update(0,
-                                                  pkt->side_data[i].data,
-                                                  pkt->side_data[i].size);
+                break;
+            case AV_PKT_DATA_CPB_PROPERTIES:
+#define BSWAP(struct, field) bswap(buf, offsetof(struct, field), sizeof(((struct){0}).field))
+                if (sd->size == sizeof(AVCPBProperties)) {
+                    memcpy(buf, sd->data, sizeof(AVCPBProperties));
+                    data = buf;
+                    BSWAP(AVCPBProperties, max_bitrate);
+                    BSWAP(AVCPBProperties, min_bitrate);
+                    BSWAP(AVCPBProperties, avg_bitrate);
+                    BSWAP(AVCPBProperties, buffer_size);
+                    BSWAP(AVCPBProperties, vbv_delay);
+                }
+                goto pod;
+            case AV_PKT_DATA_PRFT:
+                if (sd->size == sizeof(AVProducerReferenceTime)) {
+                    memcpy(buf, sd->data, sizeof(AVProducerReferenceTime));
+                    data = buf;
+                    BSWAP(AVProducerReferenceTime, wallclock);
+                    BSWAP(AVProducerReferenceTime, flags);
+                }
+                goto pod;
+            pod:
+#endif
+            default:
+                side_data_crc = av_adler32_update(0, data, sd->size);
             }
             av_strlcatf(buf, sizeof(buf), ", %8d, 0x%08"PRIx32, pkt->side_data[i].size, side_data_crc);
         }
-- 
2.25.1