diff --git a/libavcodec/adpcmenc.c b/libavcodec/adpcmenc.c
index 747b9fe4c4..284fbb60e8 100644
--- a/libavcodec/adpcmenc.c
+++ b/libavcodec/adpcmenc.c
@@ -538,8 +538,8 @@ static int adpcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                     ADPCMChannelStatus *status = &c->status[ch];
                     const int16_t *smp = &samples_p[ch][1 + i * 8];
                     for (j = 0; j < 8; j += 2) {
-                        uint8_t v =  adpcm_ima_compress_sample(status, smp[j    ]);
-                        v        |= (adpcm_ima_compress_sample(status, smp[j + 1]) << 4);
+                        uint8_t v = adpcm_ima_compress_sample(status, smp[j    ]);
+                        v        |= adpcm_ima_compress_sample(status, smp[j + 1]) << 4;
                         *dst++ = v;
                     }
                 }
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 36ac878540..be86fa0a6f 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -947,9 +947,16 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
     if (av_codec_is_encoder(avctx->codec)) {
         int i;
         if (avctx->codec->sample_fmts) {
-            for (i = 0; avctx->codec->sample_fmts[i] != AV_SAMPLE_FMT_NONE; i++)
+            for (i = 0; avctx->codec->sample_fmts[i] != AV_SAMPLE_FMT_NONE; i++) {
                 if (avctx->sample_fmt == avctx->codec->sample_fmts[i])
                     break;
+                if (avctx->channels == 1 &&
+                    av_get_planar_sample_fmt(avctx->sample_fmt) ==
+                    av_get_planar_sample_fmt(avctx->codec->sample_fmts[i])) {
+                    avctx->sample_fmt = avctx->codec->sample_fmts[i];
+                    break;
+                }
+            }
             if (avctx->codec->sample_fmts[i] == AV_SAMPLE_FMT_NONE) {
                 av_log(avctx, AV_LOG_ERROR, "Specified sample_fmt is not supported.\n");
                 ret = AVERROR(EINVAL);
diff --git a/libavdevice/timefilter.c b/libavdevice/timefilter.c
index 330f26e367..343f1b1c44 100644
--- a/libavdevice/timefilter.c
+++ b/libavdevice/timefilter.c
@@ -28,8 +28,8 @@
 #include "timefilter.h"
 
 struct TimeFilter {
-    /// Delay Locked Loop data. These variables refer to mathematical
-    /// concepts described in: http://www.kokkinizita.net/papers/usingdll.pdf
+    // Delay Locked Loop data. These variables refer to mathematical
+    // concepts described in: http://www.kokkinizita.net/papers/usingdll.pdf
     double cycle_time;
     double feedback2_factor;
     double feedback3_factor;
@@ -69,15 +69,12 @@ double ff_timefilter_update(TimeFilter *self, double system_time, double period)
 {
     self->count++;
     if (self->count == 1) {
-        /// init loop
         self->cycle_time = system_time;
     } else {
         double loop_error;
         self->cycle_time += self->clock_period * period;
-        /// calculate loop error
         loop_error = system_time - self->cycle_time;
 
-        /// update loop
         self->cycle_time   += FFMAX(self->feedback2_factor, 1.0 / self->count) * loop_error;
         self->clock_period += self->feedback3_factor * loop_error;
     }
diff --git a/libavfilter/af_resample.c b/libavfilter/af_resample.c
index c51f9d243b..58a9b2a99e 100644
--- a/libavfilter/af_resample.c
+++ b/libavfilter/af_resample.c
@@ -93,7 +93,11 @@ static int config_output(AVFilterLink *outlink)
 
     if (inlink->channel_layout == outlink->channel_layout &&
         inlink->sample_rate    == outlink->sample_rate    &&
-        inlink->format         == outlink->format)
+        (inlink->format        == outlink->format ||
+        (av_get_channel_layout_nb_channels(inlink->channel_layout)  == 1 &&
+         av_get_channel_layout_nb_channels(outlink->channel_layout) == 1 &&
+         av_get_planar_sample_fmt(inlink->format) ==
+         av_get_planar_sample_fmt(outlink->format))))
         return 0;
 
     if (!(s->avr = avresample_alloc_context()))
@@ -226,6 +230,7 @@ static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *buf)
 fail:
         avfilter_unref_buffer(buf);
     } else {
+        buf->format = outlink->format;
         ret = ff_filter_samples(outlink, buf);
         s->got_output = 1;
     }
diff --git a/libavformat/gxf.c b/libavformat/gxf.c
index 9f000d0d16..c63cafb598 100644
--- a/libavformat/gxf.c
+++ b/libavformat/gxf.c
@@ -23,6 +23,7 @@
 #include "avformat.h"
 #include "internal.h"
 #include "gxf.h"
+#include "libavcodec/mpeg12data.h"
 
 struct gxf_stream_info {
     int64_t first_field;
@@ -207,7 +208,6 @@ static void gxf_material_tags(AVIOContext *pb, int *len, struct gxf_stream_info
  * @return fps as AVRational, or 0 / 0 if unknown
  */
 static AVRational fps_tag2avr(int32_t fps) {
-    extern const AVRational avpriv_frame_rate_tab[];
     if (fps < 1 || fps > 9) fps = 9;
     return avpriv_frame_rate_tab[9 - fps]; // values have opposite order
 }