Add missing mms.c from r24779.

Originally committed as revision 24780 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/mms.c

+/*
+ * MMS protocol common definitions.
+ * Copyright (c) 2006,2007 Ryan Martell
+ * Copyright (c) 2007 Bjrn 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
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "mms.h"
+#include "asf.h"
+#include "libavutil/intreadwrite.h"
+
+int ff_mms_read_header(MMSContext *mms, uint8_t *buf, const int size)
+{
+    char *pos;
+    int size_to_copy;
+    int remaining_size = mms->asf_header_size - mms->asf_header_read_size;
+    size_to_copy = FFMIN(size, remaining_size);
+    pos = mms->asf_header + mms->asf_header_read_size;
+    memcpy(buf, pos, size_to_copy);
+    if (mms->asf_header_read_size == mms->asf_header_size) {
+        av_freep(&mms->asf_header); // which contains asf header
+    }
+    mms->asf_header_read_size += size_to_copy;
+    return size_to_copy;
+}
+
+int ff_mms_read_data(MMSContext *mms, uint8_t *buf, const int size)
+{
+    int read_size;
+    read_size = FFMIN(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;
+}
+
+int ff_mms_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;
+}