ffmpeg source update for sep 09

source/patched-ffmpeg-mt/libavformat/mmst.c

 /*
  * MMS protocol over TCP
  * Copyright (c) 2006,2007 Ryan Martell
  * Copyright (c) 2007 Björn Axelsson
  * Copyright (c) 2010 Zhentan Feng <spyfeng at gmail dot com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ skipping 11 matching lines @@
  */
 
 /* References
  * MMS protocol specification:
  *  [1]http://msdn.microsoft.com/en-us/library/cc234711(PROT.10).aspx
  * ASF specification. Revision 01.20.03.
  *  [2]http://msdn.microsoft.com/en-us/library/bb643323.aspx
  */
 
 #include "avformat.h"
+#include "mms.h"
 #include "internal.h"
 #include "libavutil/intreadwrite.h"
 #include "libavcodec/bytestream.h"
 #include "network.h"
 #include "asf.h"
 
 #define LOCAL_ADDRESS 0xc0a80081    // FIXME get and use correct local ip address.
 #define LOCAL_PORT    1037          // as above.
 /** Client to server packet types. */
 typedef enum {
@@ skipping 35 matching lines @@
     /*@}*/
 
     /** Data packets. */
     /*@{*/
     SC_PKT_ASF_HEADER               = 0x010000,// make it bigger than 0xFF in case of
     SC_PKT_ASF_MEDIA                = 0x010001,// receiving false data packets.
     /*@}*/
 } MMSSCPacketType;
 
 typedef struct {
-    int id;
-}MMSStream;
-
-typedef struct {
+    MMSContext  mms;
     int outgoing_packet_seq;             ///< Outgoing packet sequence number.
     char path[256];                      ///< Path of the resource being asked for.
     char host[128];                      ///< Host of the resources.
-
-    URLContext *mms_hd;                  ///< TCP connection handle
-    MMSStream streams[MAX_STREAMS];
-
-    /** Buffer for outgoing packets. */
-    /*@{*/
-    uint8_t *write_out_ptr;              ///< Pointer for writting the buffer.
-    uint8_t out_buffer[512];             ///< Buffer for outgoing packet.
-    /*@}*/
-
-    /** Buffer for incoming packets. */
-    /*@{*/
-    uint8_t in_buffer[8192];             ///< Buffer for incoming packets.
-    uint8_t *read_in_ptr;                ///< Pointer for reading from incoming buffer.
-    int remaining_in_len;                ///< Reading length from incoming buffer.
-    /*@}*/
-
     int incoming_packet_seq;             ///< Incoming packet sequence number.
     int incoming_flags;                  ///< Incoming packet flags.
-
     int packet_id;                       ///< Identifier for packets in the current stream.
     unsigned int header_packet_id;       ///< default is 2.
-
-    /** Internal handling of the ASF header */
-    /*@{*/
-    uint8_t *asf_header;                 ///< Stored ASF header.
-    int asf_header_size;                 ///< Size of stored ASF header.
-    int header_parsed;                   ///< The header has been received and parsed.
-    int asf_packet_len;
-    int asf_header_read_size;
-    /*@}*/
-
-    int stream_num;                      ///< stream numbers.
-} MMSContext;
+} MMSTContext;
 
 /** Create MMST command packet header */
-static void start_command_packet(MMSContext *mms, MMSCSPacketType packet_type)
+static void start_command_packet(MMSTContext *mmst, MMSCSPacketType packet_type)
 {
+    MMSContext *mms    = &mmst->mms;
     mms->write_out_ptr = mms->out_buffer;
 
     bytestream_put_le32(&mms->write_out_ptr, 1); // start sequence
     bytestream_put_le32(&mms->write_out_ptr, 0xb00bface);
     bytestream_put_le32(&mms->write_out_ptr, 0); // Length starts from after the protocol type bytes
     bytestream_put_le32(&mms->write_out_ptr, MKTAG('M','M','S',' '));
     bytestream_put_le32(&mms->write_out_ptr, 0);
-    bytestream_put_le32(&mms->write_out_ptr, mms->outgoing_packet_seq++);
+    bytestream_put_le32(&mms->write_out_ptr, mmst->outgoing_packet_seq++);
     bytestream_put_le64(&mms->write_out_ptr, 0); // timestamp
     bytestream_put_le32(&mms->write_out_ptr, 0);
     bytestream_put_le16(&mms->write_out_ptr, packet_type);
     bytestream_put_le16(&mms->write_out_ptr, 3); // direction to server
 }
 
 /** Add prefixes to MMST command packet. */
 static void insert_command_prefixes(MMSContext *mms,
         uint32_t prefix1, uint32_t prefix2)
 {
     bytestream_put_le32(&mms->write_out_ptr, prefix1); // first prefix
     bytestream_put_le32(&mms->write_out_ptr, prefix2); // second prefix
 }
 
 /** Send a prepared MMST command packet. */
-static int send_command_packet(MMSContext *mms)
+static int send_command_packet(MMSTContext *mmst)
 {
+    MMSContext *mms  = &mmst->mms;
     int len= mms->write_out_ptr - mms->out_buffer;
-    int exact_length = (len + 7) & ~7;
+    int exact_length = FFALIGN(len, 8);
     int first_length= exact_length - 16;
     int len8= first_length/8;
     int write_result;
 
     // update packet length fields.
     AV_WL32(mms->out_buffer + 8, first_length);
     AV_WL32(mms->out_buffer + 16, len8);
     AV_WL32(mms->out_buffer + 32, len8-2);
     memset(mms->write_out_ptr, 0, exact_length - len);
 
@@ skipping 16 matching lines @@
     ByteIOContext bic;
     int size = mms->write_out_ptr - mms->out_buffer;
     int len;
     init_put_byte(&bic, mms->write_out_ptr,
             sizeof(mms->out_buffer) - size, 1, NULL, NULL, NULL, NULL);
 
     len = ff_put_str16_nolen(&bic, src);
     mms->write_out_ptr += len;
 }
 
-static int send_time_test_data(MMSContext *mms)
+static int send_time_test_data(MMSTContext *mmst)
 {
-    start_command_packet(mms, CS_PKT_TIMING_DATA_REQUEST);
-    insert_command_prefixes(mms, 0xf0f0f0f1, 0x0004000b);
-    return send_command_packet(mms);
+    start_command_packet(mmst, CS_PKT_TIMING_DATA_REQUEST);
+    insert_command_prefixes(&mmst->mms, 0x00f0f0f0, 0x0004000b);
+    return send_command_packet(mmst);
 }
 
-static int send_protocol_select(MMSContext *mms)
+static int send_protocol_select(MMSTContext *mmst)
 {
     char data_string[256];
+    MMSContext *mms = &mmst->mms;
 
-    start_command_packet(mms, CS_PKT_PROTOCOL_SELECT);
+    start_command_packet(mmst, CS_PKT_PROTOCOL_SELECT);
     insert_command_prefixes(mms, 0, 0xffffffff);
     bytestream_put_le32(&mms->write_out_ptr, 0);          // maxFunnelBytes
     bytestream_put_le32(&mms->write_out_ptr, 0x00989680); // maxbitRate
     bytestream_put_le32(&mms->write_out_ptr, 2);          // funnelMode
     snprintf(data_string, sizeof(data_string), "\\\\%d.%d.%d.%d\\%s\\%d",
             (LOCAL_ADDRESS>>24)&0xff,
             (LOCAL_ADDRESS>>16)&0xff,
             (LOCAL_ADDRESS>>8)&0xff,
             LOCAL_ADDRESS&0xff,
             "TCP",                                        // or UDP
             LOCAL_PORT);
 
     mms_put_utf16(mms, data_string);
-    return send_command_packet(mms);
+    return send_command_packet(mmst);
 }
 
-static int send_media_file_request(MMSContext *mms)
+static int send_media_file_request(MMSTContext *mmst)
 {
-    start_command_packet(mms, CS_PKT_MEDIA_FILE_REQUEST);
+    MMSContext *mms = &mmst->mms;
+    start_command_packet(mmst, CS_PKT_MEDIA_FILE_REQUEST);
     insert_command_prefixes(mms, 1, 0xffffffff);
     bytestream_put_le32(&mms->write_out_ptr, 0);
     bytestream_put_le32(&mms->write_out_ptr, 0);
-    mms_put_utf16(mms, mms->path + 1); // +1 for skip "/"
+    mms_put_utf16(mms, mmst->path + 1); // +1 for skip "/"
 
-    return send_command_packet(mms);
+    return send_command_packet(mmst);
 }
 
-static void handle_packet_stream_changing_type(MMSContext *mms)
+static void handle_packet_stream_changing_type(MMSTContext *mmst)
 {
+    MMSContext *mms = &mmst->mms;
     dprintf(NULL, "Stream changing!\n");
 
     // 40 is the packet header size, 7 is the prefix size.
-    mms->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7);
-    dprintf(NULL, "Changed header prefix to 0x%x", mms->header_packet_id);
+    mmst->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7);
+    dprintf(NULL, "Changed header prefix to 0x%x", mmst->header_packet_id);
 }
 
-static int send_keepalive_packet(MMSContext *mms)
+static int send_keepalive_packet(MMSTContext *mmst)
 {
     // respond to a keepalive with a keepalive...
-    start_command_packet(mms, CS_PKT_KEEPALIVE);
-    insert_command_prefixes(mms, 1, 0x100FFFF);
-    return send_command_packet(mms);
+    start_command_packet(mmst, CS_PKT_KEEPALIVE);
+    insert_command_prefixes(&mmst->mms, 1, 0x100FFFF);
+    return send_command_packet(mmst);
 }
 
 /** Pad media packets smaller than max_packet_size and/or adjust read position
   * after a seek. */
 static void pad_media_packet(MMSContext *mms)
 {
     if(mms->remaining_in_len<mms->asf_packet_len) {
         int padding_size = mms->asf_packet_len - mms->remaining_in_len;
         memset(mms->in_buffer + mms->remaining_in_len, 0, padding_size);
         mms->remaining_in_len += padding_size;
     }
 }
 
 /** Read incoming MMST media, header or command packet. */
-static MMSSCPacketType get_tcp_server_response(MMSContext *mms)
+static MMSSCPacketType get_tcp_server_response(MMSTContext *mmst)
 {
     int read_result;
     MMSSCPacketType packet_type= -1;
-
+    MMSContext *mms = &mmst->mms;
     for(;;) {
         read_result = url_read_complete(mms->mms_hd, mms->in_buffer, 8);
         if (read_result != 8) {
             if(read_result < 0) {
                 av_log(NULL, AV_LOG_ERROR,
                        "Error reading packet header: %d (%s)\n",
                        read_result, strerror(read_result));
                 packet_type = SC_PKT_CANCEL;
             } else {
                 av_log(NULL, AV_LOG_ERROR,
                        "The server closed the connection\n");
                 packet_type = SC_PKT_NO_DATA;
             }
             return packet_type;
         }
 
         // handle command packet.
         if(AV_RL32(mms->in_buffer + 4)==0xb00bface) {
             int length_remaining, hr;
 
-            mms->incoming_flags= mms->in_buffer[3];
+            mmst->incoming_flags= mms->in_buffer[3];
             read_result= url_read_complete(mms->mms_hd, mms->in_buffer+8, 4);
             if(read_result != 4) {
                 av_log(NULL, AV_LOG_ERROR,
                        "Reading command packet length failed: %d (%s)\n",
                        read_result,
                        read_result < 0 ? strerror(read_result) :
                            "The server closed the connection");
                 return read_result < 0 ? read_result : AVERROR_IO;
             }
 
@@ skipping 26 matching lines @@
             }
         } else {
             int length_remaining;
             int packet_id_type;
             int tmp;
 
             // note we cache the first 8 bytes,
             // then fill up the buffer with the others
             tmp                       = AV_RL16(mms->in_buffer + 6);
             length_remaining          = (tmp - 8) & 0xffff;
-            mms->incoming_packet_seq  = AV_RL32(mms->in_buffer);
+            mmst->incoming_packet_seq = AV_RL32(mms->in_buffer);
             packet_id_type            = mms->in_buffer[4];
-            mms->incoming_flags       = mms->in_buffer[5];
+            mmst->incoming_flags      = mms->in_buffer[5];
 
             if (length_remaining < 0
                 || length_remaining > sizeof(mms->in_buffer) - 8) {
                 av_log(NULL, AV_LOG_ERROR,
                        "Data length %d is invalid or too large (max=%zu)\n",
                        length_remaining, sizeof(mms->in_buffer));
                 return AVERROR_INVALIDDATA;
             }
             mms->remaining_in_len    = length_remaining;
             mms->read_in_ptr         = mms->in_buffer;
             read_result= url_read_complete(mms->mms_hd, mms->in_buffer, length_remaining);
             if(read_result != length_remaining) {
                 av_log(NULL, AV_LOG_ERROR,
                        "Failed to read packet data of size %d: %d (%s)\n",
                        length_remaining, read_result,
                        read_result < 0 ? strerror(read_result) :
                            "The server closed the connection");
                 return read_result < 0 ? read_result : AVERROR_IO;
             }
 
             // if we successfully read everything.
-            if(packet_id_type == mms->header_packet_id) {
+            if(packet_id_type == mmst->header_packet_id) {
                 packet_type = SC_PKT_ASF_HEADER;
                 // Store the asf header
                 if(!mms->header_parsed) {
                     void *p = av_realloc(mms->asf_header,
                                   mms->asf_header_size + mms->remaining_in_len);
                     if (!p) {
                         av_freep(&mms->asf_header);
                         return AVERROR(ENOMEM);
                     }
                     mms->asf_header = p;
                     memcpy(mms->asf_header + mms->asf_header_size,
                            mms->read_in_ptr, mms->remaining_in_len);
                     mms->asf_header_size += mms->remaining_in_len;
                 }
                 // 0x04 means asf header is sent in multiple packets.
-                if (mms->incoming_flags == 0x04)
+                if (mmst->incoming_flags == 0x04)
                     continue;
-            } else if(packet_id_type == mms->packet_id) {
+            } else if(packet_id_type == mmst->packet_id) {
                 packet_type = SC_PKT_ASF_MEDIA;
             } else {
                 dprintf(NULL, "packet id type %d is old.", packet_id_type);
                 continue;
             }
         }
 
         // preprocess some packet type
         if(packet_type == SC_PKT_KEEPALIVE) {
-            send_keepalive_packet(mms);
+            send_keepalive_packet(mmst);
             continue;
         } else if(packet_type == SC_PKT_STREAM_CHANGING) {
-            handle_packet_stream_changing_type(mms);
+            handle_packet_stream_changing_type(mmst);
         } else if(packet_type == SC_PKT_ASF_MEDIA) {
             pad_media_packet(mms);
         }
         return packet_type;
     }
 }
 
-static int mms_safe_send_recv(MMSContext *mms,
-                              int (*send_fun)(MMSContext *mms),
+static int mms_safe_send_recv(MMSTContext *mmst,
+                              int (*send_fun)(MMSTContext *mmst),
                               const MMSSCPacketType expect_type)
 {
     MMSSCPacketType type;
     if(send_fun) {
-        int ret = send_fun(mms);
+        int ret = send_fun(mmst);
         if (ret < 0) {
             dprintf(NULL, "Send Packet error before expecting recv packet %d\n", expect_type);
             return ret;
         }
     }
 
-    if ((type = get_tcp_server_response(mms)) != expect_type) {
+    if ((type = get_tcp_server_response(mmst)) != expect_type) {
         av_log(NULL, AV_LOG_ERROR,
                "Corrupt stream (unexpected packet type 0x%x, expected 0x%x)\n",
                type, expect_type);
         return AVERROR_INVALIDDATA;
     } else {
         return 0;
     }
 }
 
-static int send_media_header_request(MMSContext *mms)
+static int send_media_header_request(MMSTContext *mmst)
 {
-    start_command_packet(mms, CS_PKT_MEDIA_HEADER_REQUEST);
+    MMSContext *mms = &mmst->mms;
+    start_command_packet(mmst, CS_PKT_MEDIA_HEADER_REQUEST);
     insert_command_prefixes(mms, 1, 0);
     bytestream_put_le32(&mms->write_out_ptr, 0);
     bytestream_put_le32(&mms->write_out_ptr, 0x00800000);
     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff);
     bytestream_put_le32(&mms->write_out_ptr, 0);
     bytestream_put_le32(&mms->write_out_ptr, 0);
     bytestream_put_le32(&mms->write_out_ptr, 0);
 
     // the media preroll value in milliseconds?
     bytestream_put_le32(&mms->write_out_ptr, 0);
     bytestream_put_le32(&mms->write_out_ptr, 0x40AC2000);
     bytestream_put_le32(&mms->write_out_ptr, 2);
     bytestream_put_le32(&mms->write_out_ptr, 0);
 
-    return send_command_packet(mms);
+    return send_command_packet(mmst);
 }
 
 /** Send the initial handshake. */
-static int send_startup_packet(MMSContext *mms)
+static int send_startup_packet(MMSTContext *mmst)
 {
     char data_string[256];
+    MMSContext *mms = &mmst->mms;
     // SubscriberName is defined in MS specification linked below.
     // The guid value can be any valid value.
     // http://download.microsoft.com/
     // download/9/5/E/95EF66AF-9026-4BB0-A41D-A4F81802D92C/%5BMS-WMSP%5D.pdf
     snprintf(data_string, sizeof(data_string),
             "NSPlayer/7.0.0.1956; {%s}; Host: %s",
-            "7E667F5D-A661-495E-A512-F55686DDA178", mms->host);
+            "7E667F5D-A661-495E-A512-F55686DDA178", mmst->host);
 
-    start_command_packet(mms, CS_PKT_INITIAL);
+    start_command_packet(mmst, CS_PKT_INITIAL);
     insert_command_prefixes(mms, 0, 0x0004000b);
     bytestream_put_le32(&mms->write_out_ptr, 0x0003001c);
     mms_put_utf16(mms, data_string);
-    return send_command_packet(mms);
-}
-
-static int asf_header_parser(MMSContext *mms)
-{
-    uint8_t *p = mms->asf_header;
-    uint8_t *end;
-    int flags, stream_id;
-    mms->stream_num = 0;
-
-    if (mms->asf_header_size < sizeof(ff_asf_guid) * 2 + 22 ||
-        memcmp(p, ff_asf_header, sizeof(ff_asf_guid))) {
-        av_log(NULL, AV_LOG_ERROR,
-               "Corrupt stream (invalid ASF header, size=%d)\n",
-               mms->asf_header_size);
-        return AVERROR_INVALIDDATA;
-    }
-
-    end = mms->asf_header + mms->asf_header_size;
-
-    p += sizeof(ff_asf_guid) + 14;
-    while(end - p >= sizeof(ff_asf_guid) + 8) {
-        uint64_t chunksize = AV_RL64(p + sizeof(ff_asf_guid));
-        if (!chunksize || chunksize > end - p) {
-            av_log(NULL, AV_LOG_ERROR,
-                   "Corrupt stream (header chunksize %"PRId64" is invalid)\n",
-                   chunksize);
-            return AVERROR_INVALIDDATA;
-        }
-        if (!memcmp(p, ff_asf_file_header, sizeof(ff_asf_guid))) {
-            /* read packet size */
-            if (end - p > sizeof(ff_asf_guid) * 2 + 68) {
-                mms->asf_packet_len = AV_RL32(p + sizeof(ff_asf_guid) * 2 + 64);
-                if (mms->asf_packet_len <= 0 || mms->asf_packet_len > sizeof(mms->in_buffer)) {
-                    av_log(NULL, AV_LOG_ERROR,
-                           "Corrupt stream (too large pkt_len %d)\n",
-                           mms->asf_packet_len);
-                    return AVERROR_INVALIDDATA;
-                }
-            }
-        } else if (!memcmp(p, ff_asf_stream_header, sizeof(ff_asf_guid))) {
-            flags     = AV_RL16(p + sizeof(ff_asf_guid)*3 + 24);
-            stream_id = flags & 0x7F;
-            //The second condition is for checking CS_PKT_STREAM_ID_REQUEST packet size,
-            //we can calcuate the packet size by stream_num.
-            //Please see function send_stream_selection_request().
-            if (mms->stream_num < MAX_STREAMS &&
-                    46 + mms->stream_num * 6 < sizeof(mms->out_buffer)) {
-                mms->streams[mms->stream_num].id = stream_id;
-                mms->stream_num++;
-            } else {
-                av_log(NULL, AV_LOG_ERROR,
-                       "Corrupt stream (too many A/V streams)\n");
-                return AVERROR_INVALIDDATA;
-            }
-        } else if (!memcmp(p, ff_asf_head1_guid, sizeof(ff_asf_guid))) {
-            chunksize = 46; // see references [2] section 3.4. This should be set 46.
-        }
-        p += chunksize;
-    }
-
-    return 0;
+    return send_command_packet(mmst);
 }
 
 /** Send MMST stream selection command based on the AVStream->discard values. */
-static int send_stream_selection_request(MMSContext *mms)
+static int send_stream_selection_request(MMSTContext *mmst)
 {
     int i;
-
+    MMSContext *mms = &mmst->mms;
     //  send the streams we want back...
-    start_command_packet(mms, CS_PKT_STREAM_ID_REQUEST);
+    start_command_packet(mmst, CS_PKT_STREAM_ID_REQUEST);
     bytestream_put_le32(&mms->write_out_ptr, mms->stream_num);         // stream nums
     for(i= 0; i<mms->stream_num; i++) {
         bytestream_put_le16(&mms->write_out_ptr, 0xffff);              // flags
         bytestream_put_le16(&mms->write_out_ptr, mms->streams[i].id);  // stream id
         bytestream_put_le16(&mms->write_out_ptr, 0);                   // selection
     }
-    return send_command_packet(mms);
+    return send_command_packet(mmst);
 }
 
-static int read_data(MMSContext *mms, uint8_t *buf, const int buf_size)
+static int send_close_packet(MMSTContext *mmst)
 {
-    int read_size;
-    read_size = FFMIN(buf_size, mms->remaining_in_len);
-    memcpy(buf, mms->read_in_ptr, read_size);
-    mms->remaining_in_len -= read_size;
-    mms->read_in_ptr      += read_size;
-    return read_size;
-}
+    start_command_packet(mmst, CS_PKT_STREAM_CLOSE);
+    insert_command_prefixes(&mmst->mms, 1, 1);
 
-static int send_close_packet(MMSContext *mms)
-{
-    start_command_packet(mms, CS_PKT_STREAM_CLOSE);
-    insert_command_prefixes(mms, 1, 1);
-
-    return send_command_packet(mms);
+    return send_command_packet(mmst);
 }
 
 /** Close the MMSH/MMST connection */
 static int mms_close(URLContext *h)
 {
-    MMSContext *mms = (MMSContext *)h->priv_data;
-
+    MMSTContext *mmst = (MMSTContext *)h->priv_data;
+    MMSContext *mms   = &mmst->mms;
     if(mms->mms_hd) {
-        send_close_packet(mms);
+        send_close_packet(mmst);
         url_close(mms->mms_hd);
     }
 
     /* free all separately allocated pointers in mms */
+    av_free(mms->streams);
     av_free(mms->asf_header);
     av_freep(&h->priv_data);
 
     return 0;
 }
 
-static int send_media_packet_request(MMSContext *mms)
+static int send_media_packet_request(MMSTContext *mmst)
 {
-    start_command_packet(mms, CS_PKT_START_FROM_PKT_ID);
+    MMSContext *mms = &mmst->mms;
+    start_command_packet(mmst, CS_PKT_START_FROM_PKT_ID);
     insert_command_prefixes(mms, 1, 0x0001FFFF);
     bytestream_put_le64(&mms->write_out_ptr, 0);          // seek timestamp
     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // unknown
     bytestream_put_le32(&mms->write_out_ptr, 0xffffffff); // packet offset
     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
     bytestream_put_byte(&mms->write_out_ptr, 0xff);       // max stream time limit
     bytestream_put_byte(&mms->write_out_ptr, 0x00);       // stream time limit flag
 
-    mms->packet_id++;                                     // new packet_id
-    bytestream_put_le32(&mms->write_out_ptr, mms->packet_id);
-    return send_command_packet(mms);
+    mmst->packet_id++;                                     // new packet_id
+    bytestream_put_le32(&mms->write_out_ptr, mmst->packet_id);
+    return send_command_packet(mmst);
 }
 
 
 static void clear_stream_buffers(MMSContext *mms)
 {
     mms->remaining_in_len = 0;
     mms->read_in_ptr      = mms->in_buffer;
 }
 
 static int mms_open(URLContext *h, const char *uri, int flags)
 {
+    MMSTContext *mmst;
     MMSContext *mms;
     int port, err;
     char tcpname[256];
 
     h->is_streamed = 1;
-    mms = h->priv_data = av_mallocz(sizeof(MMSContext));
+    mmst = h->priv_data = av_mallocz(sizeof(MMSTContext));
     if (!h->priv_data)
         return AVERROR(ENOMEM);
+    mms = &mmst->mms;
 
     // only for MMS over TCP, so set proto = NULL
     av_url_split(NULL, 0, NULL, 0,
-            mms->host, sizeof(mms->host), &port, mms->path,
-            sizeof(mms->path), uri);
+            mmst->host, sizeof(mmst->host), &port, mmst->path,
+            sizeof(mmst->path), uri);
 
     if(port<0)
         port = 1755; // defaut mms protocol port
 
     // establish tcp connection.
-    ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, mms->host, port, NULL);
+    ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, mmst->host, port, NULL);
     err = url_open(&mms->mms_hd, tcpname, URL_RDWR);
     if (err)
         goto fail;
 
-    mms->packet_id        = 3;          // default, initial value.
-    mms->header_packet_id = 2;          // default, initial value.
-    err = mms_safe_send_recv(mms, send_startup_packet, SC_PKT_CLIENT_ACCEPTED);
+    mmst->packet_id        = 3;          // default, initial value.
+    mmst->header_packet_id = 2;          // default, initial value.
+    err = mms_safe_send_recv(mmst, send_startup_packet, SC_PKT_CLIENT_ACCEPTED);
     if (err)
         goto fail;
-    err = mms_safe_send_recv(mms, send_time_test_data, SC_PKT_TIMING_TEST_REPLY);
+    err = mms_safe_send_recv(mmst, send_time_test_data, SC_PKT_TIMING_TEST_REPLY);
     if (err)
         goto fail;
-    err = mms_safe_send_recv(mms, send_protocol_select, SC_PKT_PROTOCOL_ACCEPTED);
+    err = mms_safe_send_recv(mmst, send_protocol_select, SC_PKT_PROTOCOL_ACCEPTED);
     if (err)
         goto fail;
-    err = mms_safe_send_recv(mms, send_media_file_request, SC_PKT_MEDIA_FILE_DETAILS);
+    err = mms_safe_send_recv(mmst, send_media_file_request, SC_PKT_MEDIA_FILE_DETAILS);
     if (err)
         goto fail;
-    err = mms_safe_send_recv(mms, send_media_header_request, SC_PKT_HEADER_REQUEST_ACCEPTED);
+    err = mms_safe_send_recv(mmst, send_media_header_request, SC_PKT_HEADER_REQUEST_ACCEPTED);
     if (err)
         goto fail;
-    err = mms_safe_send_recv(mms, NULL, SC_PKT_ASF_HEADER);
+    err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_HEADER);
     if (err)
         goto fail;
-    if((mms->incoming_flags != 0X08) && (mms->incoming_flags != 0X0C))
+    if((mmst->incoming_flags != 0X08) && (mmst->incoming_flags != 0X0C))
         goto fail;
-    err = asf_header_parser(mms);
+    err = ff_mms_asf_header_parser(mms);
     if (err) {
         dprintf(NULL, "asf header parsed failed!\n");
         goto fail;
     }
     mms->header_parsed = 1;
 
     if (!mms->asf_packet_len || !mms->stream_num)
         goto fail;
 
     clear_stream_buffers(mms);
-    err = mms_safe_send_recv(mms, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED);
+    err = mms_safe_send_recv(mmst, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED);
     if (err)
         goto fail;
     // send media packet request
-    err = mms_safe_send_recv(mms, send_media_packet_request, SC_PKT_MEDIA_PKT_FOLLOWS);
+    err = mms_safe_send_recv(mmst, send_media_packet_request, SC_PKT_MEDIA_PKT_FOLLOWS);
     if (err) {
         goto fail;
     }
     dprintf(NULL, "Leaving open (success)\n");
     return 0;
 fail:
     mms_close(h);
     dprintf(NULL, "Leaving open (failure: %d)\n", err);
     return err;
 }
 
 /** Read ASF data through the protocol. */
 static int mms_read(URLContext *h, uint8_t *buf, int size)
 {
     /* TODO: see tcp.c:tcp_read() about a possible timeout scheme */
-    MMSContext *mms = h->priv_data;
+    MMSTContext *mmst = h->priv_data;
+    MMSContext *mms   = &mmst->mms;
     int result = 0;
-    int size_to_copy;
 
     do {
         if(mms->asf_header_read_size < mms->asf_header_size) {
             /* Read from ASF header buffer */
-            size_to_copy= FFMIN(size,
-                                mms->asf_header_size - mms->asf_header_read_size);
-            memcpy(buf, mms->asf_header + mms->asf_header_read_size, size_to_copy);
-            mms->asf_header_read_size += size_to_copy;
-            result += size_to_copy;
-            dprintf(NULL, "Copied %d bytes from stored header. left: %d\n",
-                   size_to_copy, mms->asf_header_size - mms->asf_header_read_size);
-            if (mms->asf_header_size == mms->asf_header_read_size) {
-                av_freep(&mms->asf_header);
-            }
+            result = ff_mms_read_header(mms, buf, size);
         } else if(mms->remaining_in_len) {
             /* Read remaining packet data to buffer.
              * the result can not be zero because remaining_in_len is positive.*/
-            result = read_data(mms, buf, size);
+            result = ff_mms_read_data(mms, buf, size);
         } else {
             /* Read from network */
-            int err = mms_safe_send_recv(mms, NULL, SC_PKT_ASF_MEDIA);
+            int err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_MEDIA);
             if (err == 0) {
                 if(mms->remaining_in_len>mms->asf_packet_len) {
                     av_log(NULL, AV_LOG_ERROR,
                            "Incoming pktlen %d is larger than ASF pktsize %d\n",
                            mms->remaining_in_len, mms->asf_packet_len);
                     result= AVERROR_IO;
                 } else {
                     // copy the data to the packet buffer.
-                    result = read_data(mms, buf, size);
+                    result = ff_mms_read_data(mms, buf, size);
                     if (result == 0) {
                         dprintf(NULL, "read asf media paket size is zero!\n");
                         break;
                     }
                 }
             } else {
                 dprintf(NULL, "read packet error!\n");
                 break;
             }
         }
     } while(!result); // only return one packet.
     return result;
 }
 
 URLProtocol mmst_protocol = {
     "mmst",
     mms_open,
     mms_read,
     NULL, // write
     NULL, // seek
     mms_close,
 };