diff --git a/libav/avienc.c b/libav/avienc.c
index c971ef03ae..b894fd7280 100644
--- a/libav/avienc.c
+++ b/libav/avienc.c
@@ -31,7 +31,8 @@ typedef struct AVIIndex {
 } AVIIndex;
 
 typedef struct {
-    offset_t movi_list;
+    offset_t movi_list, frames_hdr_all, frames_hdr_strm[MAX_STREAMS];
+    int audio_strm_length[MAX_STREAMS];
     AVIIndex *first, *last;
 } AVIContext;
 
@@ -109,11 +110,36 @@ void put_bmp_header(ByteIOContext *pb, AVCodecContext *enc)
     put_le32(pb, 0);
 }
 
+void parse_specific_params(AVCodecContext *stream, int *au_byterate, int *au_ssize, int *au_scale)
+{
+    switch(stream->codec_id) {
+    case CODEC_ID_PCM_S16LE:
+       *au_scale = *au_ssize = 2*stream->channels;
+       *au_byterate = *au_ssize * stream->sample_rate;
+        break;
+    case CODEC_ID_PCM_U8:
+    case CODEC_ID_PCM_ALAW:
+    case CODEC_ID_PCM_MULAW:
+        *au_scale = *au_ssize = stream->channels;
+        *au_byterate = *au_ssize * stream->sample_rate;
+        break;
+    case CODEC_ID_MP2:
+        *au_ssize = 1;
+        *au_scale = 1;
+        *au_byterate = stream->bit_rate / 8;
+    default:
+        *au_ssize = 1;
+        *au_scale = 1; 
+        *au_byterate = stream->bit_rate / 8;
+        break;
+    }
+}
+
 static int avi_write_header(AVFormatContext *s)
 {
     AVIContext *avi;
     ByteIOContext *pb = &s->pb;
-    int bitrate, n, i, nb_frames;
+    int bitrate, n, i, nb_frames, au_byterate, au_ssize, au_scale;
     AVCodecContext *stream, *video_enc;
     offset_t list1, list2, strh, strf;
 
@@ -154,6 +180,7 @@ static int avi_write_header(AVFormatContext *s)
     put_le32(pb, bitrate / 8); /* XXX: not quite exact */
     put_le32(pb, 0); /* padding */
     put_le32(pb, AVIF_TRUSTCKTYPE | AVIF_HASINDEX | AVIF_ISINTERLEAVED); /* flags */
+    avi->frames_hdr_all = url_ftell(pb); /* remember this offset to fill later */
     put_le32(pb, nb_frames); /* nb frames, filled later */
     put_le32(pb, 0); /* initial frame */
     put_le32(pb, s->nb_streams); /* nb streams */
@@ -185,9 +212,10 @@ static int avi_write_header(AVFormatContext *s)
             put_le32(pb, 1000); /* scale */
             put_le32(pb, (1000 * stream->frame_rate) / FRAME_RATE_BASE); /* rate */
             put_le32(pb, 0); /* start */
+            avi->frames_hdr_strm[i] = url_ftell(pb); /* remember this offset to fill later */
             put_le32(pb, nb_frames); /* length, XXX: fill later */
             put_le32(pb, 1024 * 1024); /* suggested buffer size */
-            put_le32(pb, 10000); /* quality */
+            put_le32(pb, -1); /* quality */
             put_le32(pb, stream->width * stream->height * 3); /* sample size */
             put_le16(pb, 0);
             put_le16(pb, 0);
@@ -196,18 +224,20 @@ static int avi_write_header(AVFormatContext *s)
             break;
         case CODEC_TYPE_AUDIO:
             put_tag(pb, "auds");
-            put_le32(pb, 0);
+            put_le32(pb, 1); /* tag */
             put_le32(pb, 0); /* flags */
             put_le16(pb, 0); /* priority */
             put_le16(pb, 0); /* language */
             put_le32(pb, 0); /* initial frame */
-            put_le32(pb, 1); /* scale */
-            put_le32(pb, stream->bit_rate / 8); /* rate */
+            parse_specific_params(stream, &au_byterate, &au_ssize, &au_scale);
+            put_le32(pb, au_scale); /* scale */
+            put_le32(pb, au_byterate); /* rate */
             put_le32(pb, 0); /* start */
+            avi->frames_hdr_strm[i] = url_ftell(pb); /* remember this offset to fill later */
             put_le32(pb, 0); /* length, XXX: filled later */
             put_le32(pb, 12 * 1024); /* suggested buffer size */
             put_le32(pb, -1); /* quality */
-            put_le32(pb, 1); /* sample size */
+            put_le32(pb, au_ssize); /* sample size */
             put_le32(pb, 0);
             put_le32(pb, 0);
             break;
@@ -265,6 +295,8 @@ static int avi_write_packet(AVFormatContext *s, int stream_index,
         tag[3] = 'b';
         flags = 0x10;
     }
+    if (enc->codec_type == CODEC_TYPE_AUDIO) 
+       avi->audio_strm_length[stream_index] += size;
 
     if (!url_is_streamed(&s->pb)) {
         idx = malloc(sizeof(AVIIndex));
@@ -295,6 +327,8 @@ static int avi_write_trailer(AVFormatContext *s)
     ByteIOContext *pb = &s->pb;
     AVIContext *avi = s->priv_data;
     offset_t file_size, idx_chunk;
+    int n, nb_frames, au_byterate, au_ssize, au_scale;
+    AVCodecContext *stream;
     AVIIndex *idx;
 
     if (!url_is_streamed(&s->pb)) {
@@ -315,6 +349,32 @@ static int avi_write_trailer(AVFormatContext *s)
         file_size = url_ftell(pb);
         url_fseek(pb, 4, SEEK_SET);
         put_le32(pb, (UINT32)(file_size - 8));
+
+        /* Fill in frame/sample counters */
+        nb_frames = 0;
+        for(n=0;n<s->nb_streams;n++) {
+            if (avi->frames_hdr_strm[n] != 0) {
+                stream = &s->streams[n]->codec;
+                url_fseek(pb, avi->frames_hdr_strm[n], SEEK_SET);
+                if (stream->codec_type == CODEC_TYPE_VIDEO) {
+                    put_le32(pb, stream->frame_number); 
+                    if (nb_frames < stream->frame_number)
+                        nb_frames = stream->frame_number;
+                } else {
+                    if (stream->codec_id == CODEC_ID_MP2) {
+                        put_le32(pb, stream->frame_number);
+                        nb_frames += stream->frame_number;
+                    } else {
+                        parse_specific_params(stream, &au_byterate, &au_ssize, &au_scale);
+                        put_le32(pb, avi->audio_strm_length[n] / au_ssize);
+                    }
+                }
+            }
+       }
+       if (avi->frames_hdr_all != 0) {
+           url_fseek(pb, avi->frames_hdr_all, SEEK_SET);
+           put_le32(pb, nb_frames); 
+       }
         url_fseek(pb, file_size, SEEK_SET);
     }
     put_flush_packet(pb);
diff --git a/libav/wav.c b/libav/wav.c
index d367be7fe4..f909ddf738 100644
--- a/libav/wav.c
+++ b/libav/wav.c
@@ -33,7 +33,7 @@ CodecTag codec_wav_tags[] = {
 /* WAVEFORMATEX header */
 int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
 {
-    int tag, bps;
+    int tag, bps, blkalign, bytespersec;
 
     tag = codec_get_tag(codec_wav_tags, enc->codec_id);
     if (tag == 0)
@@ -41,18 +41,39 @@ int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
     put_le16(pb, tag); 
     put_le16(pb, enc->channels);
     put_le32(pb, enc->sample_rate);
-    put_le32(pb, enc->bit_rate / 8);
-    put_le16(pb, 1); /* block align */
     if (enc->codec_id == CODEC_ID_PCM_U8 ||
         enc->codec_id == CODEC_ID_PCM_ALAW ||
         enc->codec_id == CODEC_ID_PCM_MULAW) {
         bps = 8;
+    } else if (enc->codec_id == CODEC_ID_MP2) {
+        bps = 0;
     } else {
         bps = 16;
     }
-    put_le16(pb, bps); /* bits per sample */
     
-    put_le16(pb, 0); /* wav_extra_size */
+    if (enc->codec_id == CODEC_ID_MP2)
+        blkalign = 1;
+    else
+        blkalign = enc->channels*bps >> 3;
+    if (enc->codec_id == CODEC_ID_PCM_U8 ||
+        enc->codec_id == CODEC_ID_PCM_S16LE) {
+        bytespersec = enc->sample_rate * blkalign;
+    } else {
+        bytespersec = enc->bit_rate / 8;
+    }
+    put_le32(pb, bytespersec); /* bytes per second */
+    put_le16(pb, blkalign); /* block align */
+    put_le16(pb, bps); /* bits per sample */
+    if (enc->codec_id == CODEC_ID_MP2) {
+        put_le16(pb, 12); /* wav_extra_size */
+        put_le16(pb, 1); /* wID */
+        put_le32(pb, 2); /* fdwFlags */
+        put_le16(pb, 1152); /* nBlockSize */
+        put_le16(pb, 1); /* nFramesPerBlock */
+        put_le16(pb, 1393); /* nCodecDelay */
+    } else
+        put_le16(pb, 0); /* wav_extra_size */
+
     return 0;
 }