/**
* Write an RTP hint (that may contain one or more RTP packets)
* for the packets in data. data contains one or more packets with a
* BE32 size header.
*
* @param out buffer where the hints are written
* @param data buffer containing RTP packets
* @param size the size of the data buffer
* @param trk the MOVTrack for the hint track
* @param dts pointer where the timestamp for the written RTP hint is stored
* @return the number of RTP packets in the written hint
*/
static int write_hint_packets(AVIOContext *out, const uint8_t *data,
int size, MOVTrack *trk, int64_t *dts)
{
int64_t curpos;
int64_t count_pos, entries_pos;
int count = 0, entries;
count_pos = avio_tell(out);
/* RTPsample header */
avio_wb16(out, 0); /* packet count */
avio_wb16(out, 0); /* reserved */
while (size > 4) {
uint32_t packet_len = AV_RB32(data);
uint16_t seq;
uint32_t ts;
int32_t ts_diff;
data += 4;
size -= 4;
if (packet_len > size || packet_len <= 12)
break;
if (RTP_PT_IS_RTCP(data[1])) {
/* RTCP packet, just skip */
data += packet_len;
size -= packet_len;
continue;
}
if (packet_len > trk->max_packet_size)
trk->max_packet_size = packet_len;
seq = AV_RB16(&data[2]);
ts = AV_RB32(&data[4]);
if (trk->prev_rtp_ts == 0)
trk->prev_rtp_ts = ts;
/* Unwrap the 32-bit RTP timestamp that wraps around often
* into a not (as often) wrapping 64-bit timestamp. */
ts_diff = ts - trk->prev_rtp_ts;
if (ts_diff > 0) {
trk->cur_rtp_ts_unwrapped += ts_diff;
trk->prev_rtp_ts = ts;
ts_diff = 0;
}
if (*dts == AV_NOPTS_VALUE)
*dts = trk->cur_rtp_ts_unwrapped;
count++;
/* RTPpacket header */
avio_wb32(out, 0); /* relative_time */
avio_write(out, data, 2); /* RTP header */
avio_wb16(out, seq); /* RTPsequenceseed */
avio_wb16(out, ts_diff ? 4 : 0); /* reserved + flags (extra_flag) */
entries_pos = avio_tell(out);
avio_wb16(out, 0); /* entry count */
if (ts_diff) { /* if extra_flag is set */
avio_wb32(out, 16); /* extra_information_length */
avio_wb32(out, 12); /* rtpoffsetTLV box */
avio_write(out, "rtpo", 4);
avio_wb32(out, ts_diff);
}
data += 12;
size -= 12;
packet_len -= 12;
entries = 0;
/* Write one or more constructors describing the payload data */
describe_payload(data, packet_len, out, &entries, &trk->sample_queue);
data += packet_len;
size -= packet_len;
curpos = avio_tell(out);
avio_seek(out, entries_pos, SEEK_SET);
avio_wb16(out, entries);
avio_seek(out, curpos, SEEK_SET);
}
curpos = avio_tell(out);
avio_seek(out, count_pos, SEEK_SET);
avio_wb16(out, count);
avio_seek(out, curpos, SEEK_SET);
return count;
}
/**
* Write an RTP hint (that may contain one or more RTP packets)
* for the packets in data. data contains one or more packets with a
* BE32 size header.
*
* @param out buffer where the hints are written
* @param data buffer containing RTP packets
* @param size the size of the data buffer
* @param trk the MOVTrack for the hint track
* @param pts pointer where the timestamp for the written RTP hint is stored
* @return the number of RTP packets in the written hint
*/
static int write_hint_packets(ByteIOContext *out, const uint8_t *data,
int size, MOVTrack *trk, int64_t *pts)
{
int64_t curpos;
int64_t count_pos, entries_pos;
int count = 0, entries;
count_pos = url_ftell(out);
/* RTPsample header */
put_be16(out, 0); /* packet count */
put_be16(out, 0); /* reserved */
while (size > 4) {
uint32_t packet_len = AV_RB32(data);
uint16_t seq;
uint32_t ts;
data += 4;
size -= 4;
if (packet_len > size || packet_len <= 12)
break;
if (data[1] >= 200 && data[1] <= 204) {
/* RTCP packet, just skip */
data += packet_len;
size -= packet_len;
continue;
}
if (packet_len > trk->max_packet_size)
trk->max_packet_size = packet_len;
seq = AV_RB16(&data[2]);
ts = AV_RB32(&data[4]);
if (trk->prev_rtp_ts == 0)
trk->prev_rtp_ts = ts;
/* Unwrap the 32-bit RTP timestamp that wraps around often
* into a not (as often) wrapping 64-bit timestamp. */
trk->cur_rtp_ts_unwrapped += (int32_t) (ts - trk->prev_rtp_ts);
trk->prev_rtp_ts = ts;
if (*pts == AV_NOPTS_VALUE)
*pts = trk->cur_rtp_ts_unwrapped;
count++;
/* RTPpacket header */
put_be32(out, 0); /* relative_time */
put_buffer(out, data, 2); /* RTP header */
put_be16(out, seq); /* RTPsequenceseed */
put_be16(out, 0); /* reserved + flags */
entries_pos = url_ftell(out);
put_be16(out, 0); /* entry count */
data += 12;
size -= 12;
packet_len -= 12;
entries = 0;
/* Write one or more constructors describing the payload data */
describe_payload(data, packet_len, out, &entries, &trk->sample_queue);
data += packet_len;
size -= packet_len;
curpos = url_ftell(out);
url_fseek(out, entries_pos, SEEK_SET);
put_be16(out, entries);
url_fseek(out, curpos, SEEK_SET);
}
curpos = url_ftell(out);
url_fseek(out, count_pos, SEEK_SET);
put_be16(out, count);
url_fseek(out, curpos, SEEK_SET);
return count;
}
