[FFmpeg-devel] [PATCH] avcodec/hevcdec: Output MD5-message in one piece

[Andreas Rheinhardt]

Otherwise, there is no guarantee that the various av_log-messages
are not interrupted by another log statement. The latter may originate
from anywhere else, even the HEVC decoder itself, as happens when
one uses frame-threading to decode the BUMPING_A_ericsson_1.bit
sample from the FATE-suite.

Furthermore, the earlier approach suffered from the fact that
various parts of the logmsg were output with different loglevels
and that checking stopped after having encountered the first
plane with MD5 mismatch, although it is probably interesting to
know whether other planes are incorrect, too.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavcodec/hevcdec.c | 39 ++++++++++++++++++---------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c
index 2d06d09b75..3c95398b96 100644
--- a/libavcodec/hevcdec.c
+++ b/libavcodec/hevcdec.c
@@ -26,6 +26,7 @@
 #include "config_components.h"
 
 #include "libavutil/attributes.h"
+#include "libavutil/avstring.h"
 #include "libavutil/common.h"
 #include "libavutil/display.h"
 #include "libavutil/film_grain_params.h"
@@ -3374,17 +3375,12 @@ fail:
     return ret;
 }
 
-static void print_md5(void *log_ctx, int level, uint8_t md5[16])
-{
-    int i;
-    for (i = 0; i < 16; i++)
-        av_log(log_ctx, level, "%02"PRIx8, md5[i]);
-}
-
 static int verify_md5(HEVCContext *s, AVFrame *frame)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(frame->format);
+    char msg_buf[4 * (50 + 2 * 2 * 16 /* MD5-size */)];
     int pixel_shift;
+    int err = 0;
     int i, j;
 
     if (!desc)
@@ -3392,9 +3388,6 @@ static int verify_md5(HEVCContext *s, AVFrame *frame)
 
     pixel_shift = desc->comp[0].depth > 8;
 
-    av_log(s->avctx, AV_LOG_DEBUG, "Verifying checksum for frame with POC %d: ",
-           s->poc);
-
     /* the checksums are LE, so we have to byteswap for >8bpp formats
      * on BE arches */
 #if HAVE_BIGENDIAN
@@ -3407,6 +3400,7 @@ static int verify_md5(HEVCContext *s, AVFrame *frame)
     }
 #endif
 
+    msg_buf[0] = '\0';
     for (i = 0; frame->data[i]; i++) {
         int width  = s->avctx->coded_width;
         int height = s->avctx->coded_height;
@@ -3428,23 +3422,26 @@ static int verify_md5(HEVCContext *s, AVFrame *frame)
         }
         av_md5_final(s->md5_ctx, md5);
 
+#define MD5_PRI "%016" PRIx64 "%016" PRIx64
+#define MD5_PRI_ARG(buf) AV_RB64(buf), AV_RB64((const uint8_t*)(buf) + 8)
+
         if (!memcmp(md5, s->sei.picture_hash.md5[i], 16)) {
-            av_log   (s->avctx, AV_LOG_DEBUG, "plane %d - correct ", i);
-            print_md5(s->avctx, AV_LOG_DEBUG, md5);
-            av_log   (s->avctx, AV_LOG_DEBUG, "; ");
+            av_strlcatf(msg_buf, sizeof(msg_buf),
+                        "plane %d - correct " MD5_PRI "; ",
+                        i, MD5_PRI_ARG(md5));
         } else {
-            av_log   (s->avctx, AV_LOG_ERROR, "mismatching checksum of plane %d - ", i);
-            print_md5(s->avctx, AV_LOG_ERROR, md5);
-            av_log   (s->avctx, AV_LOG_ERROR, " != ");
-            print_md5(s->avctx, AV_LOG_ERROR, s->sei.picture_hash.md5[i]);
-            av_log   (s->avctx, AV_LOG_ERROR, "\n");
-            return AVERROR_INVALIDDATA;
+            av_strlcatf(msg_buf, sizeof(msg_buf),
+                       "mismatching checksum of plane %d - " MD5_PRI " != " MD5_PRI "; ",
+                        i, MD5_PRI_ARG(md5), MD5_PRI_ARG(s->sei.picture_hash.md5[i]));
+            err = AVERROR_INVALIDDATA;
         }
     }
 
-    av_log(s->avctx, AV_LOG_DEBUG, "\n");
+    av_log(s->avctx, err < 0 ? AV_LOG_ERROR : AV_LOG_DEBUG,
+           "Verifying checksum for frame with POC %d: %s\n",
+           s->poc, msg_buf);
 
-    return 0;
+    return err;
 }
 
 static int hevc_decode_extradata(HEVCContext *s, uint8_t *buf, int length, int first)
-- 
2.34.1