ffmpeg/libavformat/rtmppkt.c

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/*
* RTMP input format
* Copyright (c) 2009 Kostya Shishkov
*
* 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 "libavcodec/bytestream.h"
#include "libavutil/avstring.h"
#include "avformat.h"
#include "rtmppkt.h"
#include "flv.h"
void ff_amf_write_bool(uint8_t **dst, int val)
{
bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
bytestream_put_byte(dst, val);
}
void ff_amf_write_number(uint8_t **dst, double val)
{
bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
bytestream_put_be64(dst, av_dbl2int(val));
}
void ff_amf_write_string(uint8_t **dst, const char *str)
{
bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
bytestream_put_be16(dst, strlen(str));
bytestream_put_buffer(dst, str, strlen(str));
}
void ff_amf_write_null(uint8_t **dst)
{
bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
}
void ff_amf_write_object_start(uint8_t **dst)
{
bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
}
void ff_amf_write_field_name(uint8_t **dst, const char *str)
{
bytestream_put_be16(dst, strlen(str));
bytestream_put_buffer(dst, str, strlen(str));
}
void ff_amf_write_object_end(uint8_t **dst)
{
/* first two bytes are field name length = 0,
* AMF object should end with it and end marker
*/
bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
}
int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
int chunk_size, RTMPPacket *prev_pkt)
{
uint8_t hdr, t, buf[16];
int channel_id, timestamp, data_size, offset = 0;
uint32_t extra = 0;
enum RTMPPacketType type;
if (url_read(h, &hdr, 1) != 1)
return AVERROR(EIO);
channel_id = hdr & 0x3F;
if (channel_id < 2) { //special case for channel number >= 64
buf[1] = 0;
if (url_read_complete(h, buf, channel_id + 1) != channel_id + 1)
return AVERROR(EIO);
channel_id = AV_RL16(buf) + 64;
}
data_size = prev_pkt[channel_id].data_size;
type = prev_pkt[channel_id].type;
extra = prev_pkt[channel_id].extra;
hdr >>= 6;
if (hdr == RTMP_PS_ONEBYTE) {
timestamp = prev_pkt[channel_id].timestamp;
} else {
if (url_read_complete(h, buf, 3) != 3)
return AVERROR(EIO);
timestamp = AV_RB24(buf);
if (hdr != RTMP_PS_FOURBYTES) {
if (url_read_complete(h, buf, 3) != 3)
return AVERROR(EIO);
data_size = AV_RB24(buf);
if (url_read_complete(h, &type, 1) != 1)
return AVERROR(EIO);
if (hdr == RTMP_PS_TWELVEBYTES) {
if (url_read_complete(h, buf, 4) != 4)
return AVERROR(EIO);
extra = AV_RL32(buf);
}
}
}
if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))
return -1;
p->extra = extra;
// save history
prev_pkt[channel_id].channel_id = channel_id;
prev_pkt[channel_id].type = type;
prev_pkt[channel_id].data_size = data_size;
prev_pkt[channel_id].timestamp = timestamp;
prev_pkt[channel_id].extra = extra;
while (data_size > 0) {
int toread = FFMIN(data_size, chunk_size);
if (url_read_complete(h, p->data + offset, toread) != toread) {
ff_rtmp_packet_destroy(p);
return AVERROR(EIO);
}
data_size -= chunk_size;
offset += chunk_size;
if (data_size > 0) {
url_read_complete(h, &t, 1); //marker
if (t != (0xC0 + channel_id))
return -1;
}
}
return 0;
}
int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
int chunk_size, RTMPPacket *prev_pkt)
{
uint8_t pkt_hdr[16], *p = pkt_hdr;
int mode = RTMP_PS_TWELVEBYTES;
int off = 0;
//TODO: header compression
bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
if (mode != RTMP_PS_ONEBYTE) {
bytestream_put_be24(&p, pkt->timestamp);
if (mode != RTMP_PS_FOURBYTES) {
bytestream_put_be24(&p, pkt->data_size);
bytestream_put_byte(&p, pkt->type);
if (mode == RTMP_PS_TWELVEBYTES)
bytestream_put_le32(&p, pkt->extra);
}
}
url_write(h, pkt_hdr, p-pkt_hdr);
while (off < pkt->data_size) {
int towrite = FFMIN(chunk_size, pkt->data_size - off);
url_write(h, pkt->data + off, towrite);
off += towrite;
if (off < pkt->data_size) {
uint8_t marker = 0xC0 | pkt->channel_id;
url_write(h, &marker, 1);
}
}
return 0;
}
int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
int timestamp, int size)
{
pkt->data = av_malloc(size);
if (!pkt->data)
return AVERROR(ENOMEM);
pkt->data_size = size;
pkt->channel_id = channel_id;
pkt->type = type;
pkt->timestamp = timestamp;
pkt->extra = 0;
return 0;
}
void ff_rtmp_packet_destroy(RTMPPacket *pkt)
{
if (!pkt)
return;
av_freep(&pkt->data);
pkt->data_size = 0;
}
int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
{
const uint8_t *base = data;
if (data >= data_end)
return -1;
switch (*data++) {
case AMF_DATA_TYPE_NUMBER: return 9;
case AMF_DATA_TYPE_BOOL: return 2;
case AMF_DATA_TYPE_STRING: return 3 + AV_RB16(data);
case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
case AMF_DATA_TYPE_NULL: return 1;
case AMF_DATA_TYPE_ARRAY:
data += 4;
case AMF_DATA_TYPE_OBJECT:
for (;;) {
int size = bytestream_get_be16(&data);
int t;
if (!size) {
data++;
break;
}
if (data + size >= data_end || data + size < data)
return -1;
data += size;
t = ff_amf_tag_size(data, data_end);
if (t < 0 || data + t >= data_end)
return -1;
data += t;
}
return data - base;
case AMF_DATA_TYPE_OBJECT_END: return 1;
default: return -1;
}
}
int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
const uint8_t *name, uint8_t *dst, int dst_size)
{
int namelen = strlen(name);
int len;
if (data_end - data < 3)
return -1;
if (*data++ != AMF_DATA_TYPE_OBJECT)
return -1;
for (;;) {
int size = bytestream_get_be16(&data);
if (!size)
break;
if (data + size >= data_end || data + size < data)
return -1;
data += size;
if (size == namelen && !memcmp(data-size, name, namelen)) {
switch (*data++) {
case AMF_DATA_TYPE_NUMBER:
snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));
break;
case AMF_DATA_TYPE_BOOL:
snprintf(dst, dst_size, "%s", *data ? "true" : "false");
break;
case AMF_DATA_TYPE_STRING:
len = bytestream_get_be16(&data);
av_strlcpy(dst, data, FFMIN(len+1, dst_size));
break;
default:
return -1;
}
return 0;
}
len = ff_amf_tag_size(data, data_end);
if (len < 0 || data + len >= data_end || data + len < data)
return -1;
data += len;
}
return -1;
}