diff --git a/libavformat/codecstring.c b/libavformat/codecstring.c
index 12e0fd22c8..acd2ea3a4e 100644
--- a/libavformat/codecstring.c
+++ b/libavformat/codecstring.c
@@ -54,7 +54,8 @@ static void set_vp9_codec_str(void *logctx, const AVCodecParameters *par,
                    vpcc.profile, vpcc.level, vpcc.bitdepth);
     } else {
         // Default to just vp9 in case of error while finding out profile or level
-        av_log(logctx, AV_LOG_WARNING, "Could not find VP9 profile and/or level\n");
+        if (logctx)
+            av_log(logctx, AV_LOG_WARNING, "Could not find VP9 profile and/or level\n");
         av_bprintf(out, "vp9");
     }
 }
@@ -194,7 +195,8 @@ int ff_make_codec_str(void *logctx, const AVCodecParameters *par,
         // RFC 6381
         av_bprintf(out, "mp4v.20");
         // Unimplemented, should output ProfileLevelIndication as a decimal number
-        av_log(logctx, AV_LOG_WARNING, "Incomplete RFC 6381 codec string for mp4v\n");
+        if (logctx)
+            av_log(logctx, AV_LOG_WARNING, "Incomplete RFC 6381 codec string for mp4v\n");
     } else if (par->codec_id == AV_CODEC_ID_MP2) {
         av_bprintf(out, "mp4a.40.33");
     } else if (par->codec_id == AV_CODEC_ID_MP3) {
diff --git a/libavformat/vpcc.c b/libavformat/vpcc.c
index 6601219e6a..d2989c55de 100644
--- a/libavformat/vpcc.c
+++ b/libavformat/vpcc.c
@@ -51,7 +51,8 @@ static int get_vpx_chroma_subsampling(void *logctx,
             return VPX_SUBSAMPLING_444;
         }
     }
-    av_log(logctx, AV_LOG_ERROR, "Unsupported pixel format (%d)\n", pixel_format);
+    if (logctx)
+        av_log(logctx, AV_LOG_ERROR, "Unsupported pixel format (%d)\n", pixel_format);
     return -1;
 }
 
@@ -59,8 +60,9 @@ static int get_bit_depth(void *logctx, enum AVPixelFormat pixel_format)
 {
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pixel_format);
     if (desc == NULL) {
-        av_log(logctx, AV_LOG_ERROR, "Unsupported pixel format (%d)\n",
-               pixel_format);
+        if (logctx)
+            av_log(logctx, AV_LOG_ERROR, "Unsupported pixel format (%d)\n",
+                   pixel_format);
         return -1;
     }
     return desc->comp[0].depth;
@@ -187,7 +189,7 @@ int ff_isom_get_vpcc_features(void *logctx, const AVCodecParameters *par,
         }
     }
 
-    if (profile == AV_PROFILE_UNKNOWN || !bit_depth)
+    if ((profile == AV_PROFILE_UNKNOWN || !bit_depth) && logctx)
         av_log(logctx, AV_LOG_WARNING, "VP9 profile and/or bit depth not set or could not be derived\n");
 
     vpcc->profile            = profile;