ffmpeg/libavformat/mmst.c
Andreas Rheinhardt 7001ff74ba avformat/aviobuf: Add ffio_init_(read|write)_context()
Most users of ffio_init_context() simply want to wrap
a buffer into an AVIOContext; they do not provide
function pointers at all.

Therefore this commit adds shortcuts for these two common
operations. This also allows to accept const data when reading
(i.e. the const is now cast away at a central place in
ffio_init_read_context() instead of at several callers).
This also allows to constify the data in ff_text_init_buf().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2023-09-07 00:41:45 +02:00

640 lines
24 KiB
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
* 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
*/
/* References
* MMS protocol specification:
* [1]http://msdn.microsoft.com/en-us/library/cc234711(PROT.10).aspx
* ASF specification. Revision 01.20.03.
* [2]http://web.archive.org/web/20131203084402/http://msdn.microsoft.com/en-us/library/bb643323.aspx
*/
#include "avformat.h"
#include "mms.h"
#include "internal.h"
#include "avio_internal.h"
#include "libavutil/intreadwrite.h"
#include "libavcodec/bytestream.h"
#include "network.h"
#include "url.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 {
CS_PKT_INITIAL = 0x01,
CS_PKT_PROTOCOL_SELECT = 0x02,
CS_PKT_MEDIA_FILE_REQUEST = 0x05,
CS_PKT_START_FROM_PKT_ID = 0x07,
CS_PKT_STREAM_PAUSE = 0x09,
CS_PKT_STREAM_CLOSE = 0x0d,
CS_PKT_MEDIA_HEADER_REQUEST = 0x15,
CS_PKT_TIMING_DATA_REQUEST = 0x18,
CS_PKT_USER_PASSWORD = 0x1a,
CS_PKT_KEEPALIVE = 0x1b,
CS_PKT_STREAM_ID_REQUEST = 0x33,
} MMSCSPacketType;
/** Server to client packet types. */
typedef enum {
/** Control packets. */
/*@{*/
SC_PKT_CLIENT_ACCEPTED = 0x01,
SC_PKT_PROTOCOL_ACCEPTED = 0x02,
SC_PKT_PROTOCOL_FAILED = 0x03,
SC_PKT_MEDIA_PKT_FOLLOWS = 0x05,
SC_PKT_MEDIA_FILE_DETAILS = 0x06,
SC_PKT_HEADER_REQUEST_ACCEPTED = 0x11,
SC_PKT_TIMING_TEST_REPLY = 0x15,
SC_PKT_PASSWORD_REQUIRED = 0x1a,
SC_PKT_KEEPALIVE = 0x1b,
SC_PKT_STREAM_STOPPED = 0x1e,
SC_PKT_STREAM_CHANGING = 0x20,
SC_PKT_STREAM_ID_ACCEPTED = 0x21,
/*@}*/
/** Pseudo packets. */
/*@{*/
SC_PKT_CANCEL = -1,
SC_PKT_NO_DATA = -2,
/*@}*/
/** 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 MMSTContext {
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.
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.
} MMSTContext;
/** Create MMST command packet header */
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, 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(MMSTContext *mmst)
{
MMSContext *mms = &mmst->mms;
int len= mms->write_out_ptr - mms->out_buffer;
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);
// write it out.
write_result= ffurl_write(mms->mms_hd, mms->out_buffer, exact_length);
if(write_result != exact_length) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Failed to write data of length %d: %d (%s)\n",
exact_length, write_result,
write_result < 0 ? strerror(AVUNERROR(write_result)) :
"The server closed the connection");
return AVERROR(EIO);
}
return 0;
}
static int mms_put_utf16(MMSContext *mms, const uint8_t *src)
{
FFIOContext bic;
int size = mms->write_out_ptr - mms->out_buffer;
int len;
ffio_init_write_context(&bic, mms->write_out_ptr,
sizeof(mms->out_buffer) - size);
len = avio_put_str16le(&bic.pub, src);
if (len < 0)
return len;
mms->write_out_ptr += len;
return 0;
}
static int send_time_test_data(MMSTContext *mmst)
{
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(MMSTContext *mmst)
{
int ret;
char data_string[256];
MMSContext *mms = &mmst->mms;
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);
if ((ret = mms_put_utf16(mms, data_string)) < 0)
return ret;
return send_command_packet(mmst);
}
static int send_media_file_request(MMSTContext *mmst)
{
int ret;
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);
if ((ret = mms_put_utf16(mms, mmst->path + 1)) < 0) // +1 for skip "/"
return ret;
return send_command_packet(mmst);
}
static void handle_packet_stream_changing_type(MMSTContext *mmst)
{
MMSContext *mms = &mmst->mms;
av_log(mms->mms_hd, AV_LOG_TRACE, "Stream changing!\n");
// 40 is the packet header size, 7 is the prefix size.
mmst->header_packet_id= AV_RL32(mms->in_buffer + 40 + 7);
av_log(mms->mms_hd, AV_LOG_TRACE, "Changed header prefix to 0x%x", mmst->header_packet_id);
}
static int send_keepalive_packet(MMSTContext *mmst)
{
// respond to a keepalive with a keepalive...
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(MMSTContext *mmst)
{
int read_result;
MMSSCPacketType packet_type= -1;
MMSContext *mms = &mmst->mms;
for(;;) {
read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer, 8);
if (read_result != 8) {
if(read_result < 0) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Error reading packet header: %d (%s)\n",
read_result, strerror(AVUNERROR(read_result)));
packet_type = SC_PKT_CANCEL;
} else {
av_log(mms->mms_hd, 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;
mmst->incoming_flags= mms->in_buffer[3];
read_result= ffurl_read_complete(mms->mms_hd, mms->in_buffer+8, 4);
if(read_result != 4) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Reading command packet length failed: %d (%s)\n",
read_result,
read_result < 0 ? strerror(AVUNERROR(read_result)) :
"The server closed the connection");
return read_result < 0 ? read_result : AVERROR(EIO);
}
length_remaining= AV_RL32(mms->in_buffer+8) + 4;
av_log(mms->mms_hd, AV_LOG_TRACE, "Length remaining is %d\n", length_remaining);
// read the rest of the packet.
if (length_remaining < 0
|| length_remaining > sizeof(mms->in_buffer) - 12) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Incoming packet length %d exceeds bufsize %"SIZE_SPECIFIER"\n",
length_remaining, sizeof(mms->in_buffer) - 12);
return AVERROR_INVALIDDATA;
}
read_result = ffurl_read_complete(mms->mms_hd, mms->in_buffer + 12,
length_remaining) ;
if (read_result != length_remaining) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Reading pkt data (length=%d) failed: %d (%s)\n",
length_remaining, read_result,
read_result < 0 ? strerror(AVUNERROR(read_result)) :
"The server closed the connection");
return read_result < 0 ? read_result : AVERROR(EIO);
}
packet_type= AV_RL16(mms->in_buffer+36);
if (read_result >= 44 && (hr = AV_RL32(mms->in_buffer + 40))) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Server sent a message with packet type 0x%x and error status code 0x%08x\n", packet_type, hr);
return AVERROR(EINVAL);
}
} 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;
mmst->incoming_packet_seq = AV_RL32(mms->in_buffer);
packet_id_type = mms->in_buffer[4];
mmst->incoming_flags = mms->in_buffer[5];
if (length_remaining < 0
|| length_remaining > sizeof(mms->in_buffer) - 8) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Data length %d is invalid or too large (max=%"SIZE_SPECIFIER")\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= ffurl_read_complete(mms->mms_hd, mms->in_buffer, length_remaining);
if(read_result != length_remaining) {
av_log(mms->mms_hd, AV_LOG_ERROR,
"Failed to read packet data of size %d: %d (%s)\n",
length_remaining, read_result,
read_result < 0 ? strerror(AVUNERROR(read_result)) :
"The server closed the connection");
return read_result < 0 ? read_result : AVERROR(EIO);
}
// if we successfully read everything.
if(packet_id_type == mmst->header_packet_id) {
int err;
packet_type = SC_PKT_ASF_HEADER;
// Store the asf header
if(!mms->header_parsed) {
if ((err = av_reallocp(&mms->asf_header,
mms->asf_header_size +
mms->remaining_in_len)) < 0) {
mms->asf_header_size = 0;
return err;
}
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 (mmst->incoming_flags == 0x04)
continue;
} else if(packet_id_type == mmst->packet_id) {
packet_type = SC_PKT_ASF_MEDIA;
} else {
av_log(mms->mms_hd, AV_LOG_TRACE, "packet id type %d is old.", packet_id_type);
continue;
}
}
// preprocess some packet type
if(packet_type == SC_PKT_KEEPALIVE) {
send_keepalive_packet(mmst);
continue;
} else if(packet_type == SC_PKT_STREAM_CHANGING) {
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(MMSTContext *mmst,
int (*send_fun)(MMSTContext *mmst),
const MMSSCPacketType expect_type)
{
MMSSCPacketType type;
if(send_fun) {
int ret = send_fun(mmst);
if (ret < 0) {
av_log(NULL, AV_LOG_TRACE, "Send Packet error before expecting recv packet %d\n", expect_type);
return ret;
}
}
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(MMSTContext *mmst)
{
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(mmst);
}
/** Send the initial handshake. */
static int send_startup_packet(MMSTContext *mmst)
{
char data_string[256];
int ret;
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", mmst->host);
start_command_packet(mmst, CS_PKT_INITIAL);
insert_command_prefixes(mms, 0, 0x0004000b);
bytestream_put_le32(&mms->write_out_ptr, 0x0003001c);
if ((ret = mms_put_utf16(mms, data_string)) < 0)
return ret;
return send_command_packet(mmst);
}
/** Send MMST stream selection command based on the AVStream->discard values. */
static int send_stream_selection_request(MMSTContext *mmst)
{
int i;
MMSContext *mms = &mmst->mms;
// send the streams we want back...
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(mmst);
}
static int send_close_packet(MMSTContext *mmst)
{
start_command_packet(mmst, CS_PKT_STREAM_CLOSE);
insert_command_prefixes(&mmst->mms, 1, 1);
return send_command_packet(mmst);
}
/** Close the MMSH/MMST connection */
static int mms_close(URLContext *h)
{
MMSTContext *mmst = (MMSTContext *)h->priv_data;
MMSContext *mms = &mmst->mms;
if(mms->mms_hd) {
send_close_packet(mmst);
ffurl_closep(&mms->mms_hd);
}
/* free all separately allocated pointers in mms */
av_freep(&mms->streams);
av_freep(&mms->asf_header);
return 0;
}
static int send_media_packet_request(MMSTContext *mmst)
{
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
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 = h->priv_data;
MMSContext *mms;
int port, err;
char tcpname[256];
h->is_streamed = 1;
mms = &mmst->mms;
// only for MMS over TCP, so set proto = NULL
av_url_split(NULL, 0, NULL, 0,
mmst->host, sizeof(mmst->host), &port, mmst->path,
sizeof(mmst->path), uri);
if(port<0)
port = 1755; // default MMS protocol port
// establish tcp connection.
ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, mmst->host, port, NULL);
err = ffurl_open_whitelist(&mms->mms_hd, tcpname, AVIO_FLAG_READ_WRITE,
&h->interrupt_callback, NULL,
h->protocol_whitelist, h->protocol_blacklist, h);
if (err)
goto fail;
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(mmst, send_time_test_data, SC_PKT_TIMING_TEST_REPLY);
if (err)
goto fail;
err = mms_safe_send_recv(mmst, send_protocol_select, SC_PKT_PROTOCOL_ACCEPTED);
if (err)
goto fail;
err = mms_safe_send_recv(mmst, send_media_file_request, SC_PKT_MEDIA_FILE_DETAILS);
if (err)
goto fail;
err = mms_safe_send_recv(mmst, send_media_header_request, SC_PKT_HEADER_REQUEST_ACCEPTED);
if (err)
goto fail;
err = mms_safe_send_recv(mmst, NULL, SC_PKT_ASF_HEADER);
if (err)
goto fail;
if((mmst->incoming_flags != 0X08) && (mmst->incoming_flags != 0X0C)) {
av_log(h, AV_LOG_ERROR,
"The server does not support MMST (try MMSH or RTSP)\n");
err = AVERROR(EINVAL);
goto fail;
}
err = ff_mms_asf_header_parser(mms);
if (err) {
av_log(h, AV_LOG_TRACE, "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(mmst, send_stream_selection_request, SC_PKT_STREAM_ID_ACCEPTED);
if (err)
goto fail;
// send media packet request
err = mms_safe_send_recv(mmst, send_media_packet_request, SC_PKT_MEDIA_PKT_FOLLOWS);
if (err) {
goto fail;
}
av_log(h, AV_LOG_TRACE, "Leaving open (success)\n");
return 0;
fail:
mms_close(h);
av_log(mms->mms_hd, AV_LOG_TRACE, "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 */
MMSTContext *mmst = h->priv_data;
MMSContext *mms = &mmst->mms;
int result = 0;
do {
if(mms->asf_header_read_size < mms->asf_header_size) {
/* Read from ASF header buffer */
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 = ff_mms_read_data(mms, buf, size);
} else {
/* Read from network */
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(h, AV_LOG_ERROR,
"Incoming pktlen %d is larger than ASF pktsize %d\n",
mms->remaining_in_len, mms->asf_packet_len);
result= AVERROR(EIO);
} else {
// copy the data to the packet buffer.
result = ff_mms_read_data(mms, buf, size);
if (result == 0) {
av_log(h, AV_LOG_TRACE, "Read ASF media packet size is zero!\n");
break;
}
}
} else {
av_log(h, AV_LOG_TRACE, "read packet error!\n");
break;
}
}
} while(!result); // only return one packet.
return result;
}
const URLProtocol ff_mmst_protocol = {
.name = "mmst",
.url_open = mms_open,
.url_read = mms_read,
.url_close = mms_close,
.priv_data_size = sizeof(MMSTContext),
.flags = URL_PROTOCOL_FLAG_NETWORK,
};