diff --git a/libavdevice/bktr.c b/libavdevice/bktr.c
index aa3055d946..f1ae9ea685 100644
--- a/libavdevice/bktr.c
+++ b/libavdevice/bktr.c
@@ -263,7 +263,7 @@ static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
 #endif
 
     if ((ret = av_parse_video_size(&width, &height, s->video_size)) < 0) {
-        av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
+        av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n", s->video_size);
         goto out;
     }
 
@@ -278,7 +278,7 @@ static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
             goto out;
         }
     if ((ret = av_parse_video_rate(&framerate, s->framerate)) < 0) {
-        av_log(s1, AV_LOG_ERROR, "Couldn't parse framerate.\n");
+        av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", s->framerate);
         goto out;
     }
 #if FF_API_FORMAT_PARAMETERS
diff --git a/libavdevice/fbdev.c b/libavdevice/fbdev.c
index 68a52693fd..2f3e0ff937 100644
--- a/libavdevice/fbdev.c
+++ b/libavdevice/fbdev.c
@@ -104,7 +104,7 @@ av_cold static int fbdev_read_header(AVFormatContext *avctx,
 
     ret = av_parse_video_rate(&fbdev->framerate_q, fbdev->framerate);
     if (ret < 0) {
-        av_log(avctx, AV_LOG_ERROR, "Couldn't parse framerate.\n");
+        av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", fbdev->framerate);
         return ret;
     }
 #if FF_API_FORMAT_PARAMETERS
diff --git a/libavdevice/libdc1394.c b/libavdevice/libdc1394.c
index 622579bc92..bf4e27e51b 100644
--- a/libavdevice/libdc1394.c
+++ b/libavdevice/libdc1394.c
@@ -134,11 +134,11 @@ static inline int dc1394_read_common(AVFormatContext *c, AVFormatParameters *ap,
     }
 
     if ((ret = av_parse_video_size(&width, &height, dc1394->video_size)) < 0) {
-        av_log(c, AV_LOG_ERROR, "Couldn't parse video size.\n");
+        av_log(c, AV_LOG_ERROR, "Could not parse video size '%s'.\n", dc1394->video_size);
         goto out;
     }
     if ((ret = av_parse_video_rate(&framerate, dc1394->framerate)) < 0) {
-        av_log(c, AV_LOG_ERROR, "Couldn't parse framerate.\n");
+        av_log(c, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", dc1394->framerate);
         goto out;
     }
 #if FF_API_FORMAT_PARAMETERS
diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
index b024c48d2e..072be48d40 100644
--- a/libavdevice/v4l2.c
+++ b/libavdevice/v4l2.c
@@ -460,7 +460,7 @@ static int v4l2_set_parameters(AVFormatContext *s1, AVFormatParameters *ap)
     streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 
     if (s->framerate && (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
-        av_log(s1, AV_LOG_ERROR, "Couldn't parse framerate.\n");
+        av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", s->framerate);
         return ret;
     }
 #if FF_API_FORMAT_PARAMETERS
@@ -601,7 +601,7 @@ static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 
     if (s->video_size && (res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
-        av_log(s1, AV_LOG_ERROR, "Couldn't parse video size.\n");
+        av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n", s->video_size);
         goto out;
     }
     if (s->pixel_format && (pix_fmt = av_get_pix_fmt(s->pixel_format)) == PIX_FMT_NONE) {