diff --git a/libavformat/amr.c b/libavformat/amr.c
index 3b78ba3659..fd43283a22 100644
--- a/libavformat/amr.c
+++ b/libavformat/amr.c
@@ -40,11 +40,11 @@ static int amr_write_header(AVFormatContext *s)
 
     if (enc->codec_id == CODEC_ID_AMR_NB)
     {
-        put_tag(pb, AMR_header);       /* magic number */
+        avio_write(pb, AMR_header,   sizeof(AMR_header)   - 1); /* magic number */
     }
     else if(enc->codec_id == CODEC_ID_AMR_WB)
     {
-        put_tag(pb, AMRWB_header);       /* magic number */
+        avio_write(pb, AMRWB_header, sizeof(AMRWB_header) - 1); /* magic number */
     }
     else
     {
diff --git a/libavformat/ffmetaenc.c b/libavformat/ffmetaenc.c
index 322ec0f576..77db0b9bf8 100644
--- a/libavformat/ffmetaenc.c
+++ b/libavformat/ffmetaenc.c
@@ -50,7 +50,7 @@ static void write_tags(AVIOContext *s, AVMetadata *m)
 
 static int write_header(AVFormatContext *s)
 {
-    put_tag(s->pb, ID_STRING);
+    avio_write(s->pb, ID_STRING, sizeof(ID_STRING) - 1);
     avio_w8(s->pb, '1');          // version
     avio_w8(s->pb, '\n');
     put_flush_packet(s->pb);
@@ -64,14 +64,14 @@ static int write_trailer(AVFormatContext *s)
     write_tags(s->pb, s->metadata);
 
     for (i = 0; i < s->nb_streams; i++) {
-        put_tag(s->pb, ID_STREAM);
+        avio_write(s->pb, ID_STREAM, sizeof(ID_STREAM) - 1);
         avio_w8(s->pb, '\n');
         write_tags(s->pb, s->streams[i]->metadata);
     }
 
     for (i = 0; i < s->nb_chapters; i++) {
         AVChapter *ch = s->chapters[i];
-        put_tag(s->pb, ID_CHAPTER);
+        avio_write(s->pb, ID_CHAPTER, sizeof(ID_CHAPTER) - 1);
         avio_w8(s->pb, '\n');
         url_fprintf(s->pb, "TIMEBASE=%d/%d\n", ch->time_base.num, ch->time_base.den);
         url_fprintf(s->pb, "START=%"PRId64"\n", ch->start);
diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index 71a3784396..4d49a966e9 100644
--- a/libavformat/flvenc.c
+++ b/libavformat/flvenc.c
@@ -199,7 +199,7 @@ static int flv_write_header(AVFormatContext *s)
         }
         av_set_pts_info(s->streams[i], 32, 1, 1000); /* 32 bit pts in ms */
     }
-    put_tag(pb,"FLV");
+    avio_write(pb, "FLV", 3);
     avio_w8(pb,1);
     avio_w8(pb,   FLV_HEADER_FLAG_HASAUDIO * !!audio_enc
                  + FLV_HEADER_FLAG_HASVIDEO * !!video_enc);
diff --git a/libavformat/gif.c b/libavformat/gif.c
index f3f64d1fcc..17effaaa46 100644
--- a/libavformat/gif.c
+++ b/libavformat/gif.c
@@ -114,8 +114,8 @@ static int gif_image_write_header(AVIOContext *pb,
     int i;
     unsigned int v;
 
-    put_tag(pb, "GIF");
-    put_tag(pb, "89a");
+    avio_write(pb, "GIF", 3);
+    avio_write(pb, "89a", 3);
     avio_wl16(pb, width);
     avio_wl16(pb, height);
 
@@ -162,7 +162,7 @@ static int gif_image_write_header(AVIOContext *pb,
     avio_w8(pb, 0x21);
     avio_w8(pb, 0xff);
     avio_w8(pb, 0x0b);
-        put_tag(pb, "NETSCAPE2.0");  // bytes 4 to 14
+        avio_write(pb, "NETSCAPE2.0", sizeof("NETSCAPE2.0") - 1);  // bytes 4 to 14
         avio_w8(pb, 0x03); // byte 15
         avio_w8(pb, 0x01); // byte 16
         avio_wl16(pb, (uint16_t)loop_count);
diff --git a/libavformat/gxfenc.c b/libavformat/gxfenc.c
index fb6f441f3e..1b12f41e22 100644
--- a/libavformat/gxfenc.c
+++ b/libavformat/gxfenc.c
@@ -224,7 +224,7 @@ static int gxf_write_track_description(AVFormatContext *s, GXFStreamContext *sc,
     /* media file name */
     avio_w8(pb, TRACK_NAME);
     avio_w8(pb, strlen(ES_NAME_PATTERN) + 3);
-    put_tag(pb, ES_NAME_PATTERN);
+    avio_write(pb, ES_NAME_PATTERN, sizeof(ES_NAME_PATTERN) - 1);
     avio_wb16(pb, sc->media_info);
     avio_w8(pb, 0);
 
@@ -269,6 +269,7 @@ static int gxf_write_material_data_section(AVFormatContext *s)
     GXFContext *gxf = s->priv_data;
     AVIOContext *pb = s->pb;
     int64_t pos;
+    int len;
     const char *filename = strrchr(s->filename, '/');
 
     pos = url_ftell(pb);
@@ -279,10 +280,12 @@ static int gxf_write_material_data_section(AVFormatContext *s)
         filename++;
     else
         filename = s->filename;
+    len = strlen(filename);
+
     avio_w8(pb, MAT_NAME);
-    avio_w8(pb, strlen(SERVER_PATH) + strlen(filename) + 1);
-    put_tag(pb, SERVER_PATH);
-    put_tag(pb, filename);
+    avio_w8(pb, strlen(SERVER_PATH) + len + 1);
+    avio_write(pb, SERVER_PATH, sizeof(SERVER_PATH) - 1);
+    avio_write(pb, filename, len);
     avio_w8(pb, 0);
 
     /* first field */
diff --git a/libavformat/mmf.c b/libavformat/mmf.c
index 76b27dd71e..bcb862c4b5 100644
--- a/libavformat/mmf.c
+++ b/libavformat/mmf.c
@@ -79,7 +79,7 @@ static int mmf_write_header(AVFormatContext *s)
     avio_w8(pb, 0); /* code type */
     avio_w8(pb, 0); /* status */
     avio_w8(pb, 0); /* counts */
-    put_tag(pb, "VN:libavcodec,"); /* metadata ("ST:songtitle,VN:version,...") */
+    avio_write(pb, "VN:libavcodec,", sizeof("VN:libavcodec,") -1); /* metadata ("ST:songtitle,VN:version,...") */
     end_tag_be(pb, pos);
 
     avio_write(pb, "ATR\x00", 4);
diff --git a/libavformat/rmenc.c b/libavformat/rmenc.c
index 5d311d3599..29a6a35d18 100644
--- a/libavformat/rmenc.c
+++ b/libavformat/rmenc.c
@@ -184,7 +184,7 @@ static int rv10_write_header(AVFormatContext *ctx,
             coded_frame_size = (stream->enc->bit_rate *
                                 stream->enc->frame_size) / (8 * sample_rate);
             /* audio codec info */
-            put_tag(s, ".ra");
+            avio_write(s, ".ra", 3);
             avio_w8(s, 0xfd);
             avio_wb32(s, 0x00040000); /* version */
             ffio_wfourcc(s, ".ra4");
diff --git a/libavformat/swfenc.c b/libavformat/swfenc.c
index c698600bdd..296b9c27d9 100644
--- a/libavformat/swfenc.c
+++ b/libavformat/swfenc.c
@@ -229,7 +229,7 @@ static int swf_write_header(AVFormatContext *s)
     else
         swf->samples_per_frame = (swf->audio_enc->sample_rate * rate_base) / rate;
 
-    put_tag(pb, "FWS");
+    avio_write(pb, "FWS", 3);
 
     if (!strcmp("avm2", s->oformat->name))
         version = 9;
@@ -361,7 +361,7 @@ static int swf_write_video(AVFormatContext *s,
             avio_wl16(pb, VIDEO_ID);
             put_swf_matrix(pb, 1 << FRAC_BITS, 0, 0, 1 << FRAC_BITS, 0, 0);
             avio_wl16(pb, swf->video_frame_number);
-            put_tag(pb, "video");
+            avio_write(pb, "video", 5);
             avio_w8(pb, 0x00);
             put_swf_end_tag(s);
         } else {