diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 499cff7cff06d4c0385f033bac0e445ca7047fdb..3f6ee75661f43dadde5e9f06e65d158ed954011e 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -39,6 +39,7 @@ enum CodecType {
 };
 
 enum PixelFormat {
+    PIX_FMT_ANY,
     PIX_FMT_YUV420P,
     PIX_FMT_YUV422,
     PIX_FMT_RGB24,
@@ -98,7 +99,7 @@ typedef struct AVCodecContext {
 #define FF_ASPECT_16_9_625 4
 #define FF_ASPECT_16_9_525 5
     int gop_size; /* 0 = intra only */
-    int pix_fmt;  /* pixel format, see PIX_FMT_xxx */
+    enum PixelFormat pix_fmt;  /* pixel format, see PIX_FMT_xxx */
 
     /* if non NULL, 'draw_horiz_band' is called by the libavcodec
        decoder to draw an horizontal band. It improve cache usage. Not
diff --git a/libavcodec/imgconvert.c b/libavcodec/imgconvert.c
index d39b6c1e9b52dcef8e999ca4cb113829284d45d1..b3f9a367bf195fe6abfec8975563648b7622e8a6 100644
--- a/libavcodec/imgconvert.c
+++ b/libavcodec/imgconvert.c
@@ -361,6 +361,8 @@ int img_convert(AVPicture *dst, int dst_pix_fmt,
 {
     int i;
 
+    assert(pix_fmt != PIX_FMT_ANY && dst_pix_fmt != PIX_FMT_ANY);
+
     if (dst_pix_fmt == pix_fmt) {
         switch(pix_fmt) {
         case PIX_FMT_YUV420P:
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 417c63ea63e1c9c3b0da8ed1f68baf7268a73eb8..778ef764704e8ecca68c21c16b416e5e507821c5 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -286,6 +286,8 @@ int MPV_encode_init(AVCodecContext *avctx)
     MpegEncContext *s = avctx->priv_data;
     int i;
 
+    avctx->pix_fmt = PIX_FMT_YUV420P;
+
     s->bit_rate = avctx->bit_rate;
     s->bit_rate_tolerance = avctx->bit_rate_tolerance;
     s->frame_rate = avctx->frame_rate;
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 9a4abaa9ba378810a7b742d285a2af5c333ba163..815d2157571f642573e42ae0baa59cc2d9ff92c3 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -205,6 +205,7 @@ AVCodec *avcodec_find(enum CodecID id)
 }
 
 const char *pix_fmt_str[] = {
+    "??",
     "yuv420p",
     "yuv422",
     "rgb24",
@@ -259,6 +260,9 @@ void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode)
                      enc->width, enc->height, 
                      (float)enc->frame_rate / FRAME_RATE_BASE);
         }
+        snprintf(buf + strlen(buf), buf_size - strlen(buf),
+                ", q=%d-%d", enc->qmin, enc->qmax);
+
         bitrate = enc->bit_rate;
         break;
     case CODEC_TYPE_AUDIO: