diff --git a/doc/filters.texi b/doc/filters.texi
index c70ddf3b50..01eb8935b8 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4447,6 +4447,10 @@ and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
 which @code{fieldmatch} is based on. While the semantic and usage are very
 close, some behaviour and options names can differ.
 
+The filter currently only works for constant frame rate input. Do not use it
+if your input has mixed telecined and progressive content with changing
+framerate.
+
 The filter accepts the following options:
 
 @table @option
diff --git a/libavcodec/libmp3lame.c b/libavcodec/libmp3lame.c
index 661d1c05e4..d8a444dc98 100644
--- a/libavcodec/libmp3lame.c
+++ b/libavcodec/libmp3lame.c
@@ -106,9 +106,7 @@ static av_cold int mp3lame_encode_init(AVCodecContext *avctx)
     lame_set_out_samplerate(s->gfp, avctx->sample_rate);
 
     /* algorithmic quality */
-    if (avctx->compression_level == FF_COMPRESSION_DEFAULT)
-        lame_set_quality(s->gfp, 5);
-    else
+    if (avctx->compression_level != FF_COMPRESSION_DEFAULT)
         lame_set_quality(s->gfp, avctx->compression_level);
 
     /* rate control */
diff --git a/libavdevice/v4l2.c b/libavdevice/v4l2.c
index cf7a92cdd4..59bb78b13c 100644
--- a/libavdevice/v4l2.c
+++ b/libavdevice/v4l2.c
@@ -806,6 +806,13 @@ static int device_try_init(AVFormatContext *ctx,
     return ret;
 }
 
+static int v4l2_read_probe(AVProbeData *p)
+{
+    if (av_strstart(p->filename, "/dev/video", NULL))
+        return AVPROBE_SCORE_MAX - 1;
+    return 0;
+}
+
 static int v4l2_read_header(AVFormatContext *ctx)
 {
     struct video_data *s = ctx->priv_data;
@@ -1033,6 +1040,7 @@ AVInputFormat ff_v4l2_demuxer = {
     .name           = "video4linux2,v4l2",
     .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
     .priv_data_size = sizeof(struct video_data),
+    .read_probe     = v4l2_read_probe,
     .read_header    = v4l2_read_header,
     .read_packet    = v4l2_read_packet,
     .read_close     = v4l2_read_close,
diff --git a/libavformat/assdec.c b/libavformat/assdec.c
index ccbf4c00cd..c62e76f0dd 100644
--- a/libavformat/assdec.c
+++ b/libavformat/assdec.c
@@ -112,7 +112,7 @@ static int ass_read_header(AVFormatContext *s)
     int res = 0;
     AVStream *st;
     FFTextReader tr;
-    ff_text_init_avio(&tr, s->pb);
+    ff_text_init_avio(s, &tr, s->pb);
 
     st = avformat_new_stream(s, NULL);
     if (!st)
diff --git a/libavformat/realtextdec.c b/libavformat/realtextdec.c
index 19af10830b..fff85d6ba9 100644
--- a/libavformat/realtextdec.c
+++ b/libavformat/realtextdec.c
@@ -65,7 +65,7 @@ static int realtext_read_header(AVFormatContext *s)
     char c = 0;
     int res = 0, duration = read_ts("60"); // default duration is 60 seconds
     FFTextReader tr;
-    ff_text_init_avio(&tr, s->pb);
+    ff_text_init_avio(s, &tr, s->pb);
 
     if (!st)
         return AVERROR(ENOMEM);
diff --git a/libavformat/samidec.c b/libavformat/samidec.c
index 4dbf2cf945..948e1ed8b1 100644
--- a/libavformat/samidec.c
+++ b/libavformat/samidec.c
@@ -54,7 +54,7 @@ static int sami_read_header(AVFormatContext *s)
     char c = 0;
     int res = 0, got_first_sync_point = 0;
     FFTextReader tr;
-    ff_text_init_avio(&tr, s->pb);
+    ff_text_init_avio(s, &tr, s->pb);
 
     if (!st)
         return AVERROR(ENOMEM);
diff --git a/libavformat/srtdec.c b/libavformat/srtdec.c
index 02d75f1bf1..b35e50fc36 100644
--- a/libavformat/srtdec.c
+++ b/libavformat/srtdec.c
@@ -87,7 +87,7 @@ static int srt_read_header(AVFormatContext *s)
     AVStream *st = avformat_new_stream(s, NULL);
     int res = 0;
     FFTextReader tr;
-    ff_text_init_avio(&tr, s->pb);
+    ff_text_init_avio(s, &tr, s->pb);
 
     if (!st)
         return AVERROR(ENOMEM);
diff --git a/libavformat/subtitles.c b/libavformat/subtitles.c
index 95faca6e48..7f4bdef45e 100644
--- a/libavformat/subtitles.c
+++ b/libavformat/subtitles.c
@@ -24,7 +24,7 @@
 #include "libavutil/avassert.h"
 #include "libavutil/avstring.h"
 
-void ff_text_init_avio(FFTextReader *r, AVIOContext *pb)
+void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb)
 {
     int i;
     r->pb = pb;
@@ -45,13 +45,16 @@ void ff_text_init_avio(FFTextReader *r, AVIOContext *pb)
             r->buf_pos += 3;
         }
     }
+    if (s && (r->type == FF_UTF16LE || r->type == FF_UTF16BE))
+        av_log(s, AV_LOG_WARNING,
+               "UTF16 is automatically converted to UTF8, do not specify a character encoding\n");
 }
 
 void ff_text_init_buf(FFTextReader *r, void *buf, size_t size)
 {
     memset(&r->buf_pb, 0, sizeof(r->buf_pb));
     ffio_init_context(&r->buf_pb, buf, size, 0, NULL, NULL, NULL, NULL);
-    ff_text_init_avio(r, &r->buf_pb);
+    ff_text_init_avio(NULL, r, &r->buf_pb);
 }
 
 int64_t ff_text_pos(FFTextReader *r)
diff --git a/libavformat/subtitles.h b/libavformat/subtitles.h
index 903c24d9df..eb719ea770 100644
--- a/libavformat/subtitles.h
+++ b/libavformat/subtitles.h
@@ -49,14 +49,16 @@ typedef struct {
  * Initialize the FFTextReader from the given AVIOContext. This function will
  * read some bytes from pb, and test for UTF-8 or UTF-16 BOMs. Further accesses
  * to FFTextReader will read more data from pb.
+ * If s is not NULL, the user will be warned if a UTF-16 conversion takes place.
  *
  * The purpose of FFTextReader is to transparently convert read data to UTF-8
  * if the stream had a UTF-16 BOM.
  *
+ * @param s Pointer to provide av_log context
  * @param r object which will be initialized
  * @param pb stream to read from (referenced as long as FFTextReader is in use)
  */
-void ff_text_init_avio(FFTextReader *r, AVIOContext *pb);
+void ff_text_init_avio(void *s, FFTextReader *r, AVIOContext *pb);
 
 /**
  * Similar to ff_text_init_avio(), but sets it up to read from a bounded buffer.