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git-svn-id: http://webrtc.googlecode.com/svn/trunk@172 4adac7df-926f-26a2-2b94-8c16560cd09d

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This commit is contained in:
niklase@google.com 2011-07-07 09:40:48 +00:00
parent c7f3804131
commit 0c3e855793
1 changed files with 94 additions and 35 deletions
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123
src/modules/rtp_rtcp/source/rtp_format_vp8.cc
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@ -11,7 +11,6 @@
#include "rtp_format_vp8.h"
#include <cassert> // assert
#include <math.h> // ceil
#include <string.h> // memcpy
namespace webrtc {
@ -20,13 +19,14 @@ namespace webrtc {
// Modes are: kStrict, kAggregate, kSloppy.
const RtpFormatVp8::AggregationMode RtpFormatVp8::aggr_modes_[kNumModes] =
{ kAggrNone, kAggrPartitions, kAggrFragments };
const bool RtpFormatVp8::bal_modes_[kNumModes] =
const bool RtpFormatVp8::balance_modes_[kNumModes] =
{ true, false, false };
const bool RtpFormatVp8::sep_first_modes_[kNumModes] =
const bool RtpFormatVp8::separate_first_modes_[kNumModes] =
{ true, false, false };
RtpFormatVp8::RtpFormatVp8(const WebRtc_UWord8* payload_data,
WebRtc_UWord32 payload_size,
const RTPVideoHeaderVP8& hdr_info,
const RTPFragmentationHeader& fragmentation,
VP8PacketizerMode mode)
: payload_data_(payload_data),
@ -37,14 +37,16 @@ RtpFormatVp8::RtpFormatVp8(const WebRtc_UWord8* payload_data,
first_fragment_(true),
vp8_header_bytes_(1),
aggr_mode_(aggr_modes_[mode]),
balance_(bal_modes_[mode]),
separate_first_(sep_first_modes_[mode])
balance_(balance_modes_[mode]),
separate_first_(separate_first_modes_[mode]),
hdr_info_(hdr_info)
{
part_info_ = fragmentation;
}
RtpFormatVp8::RtpFormatVp8(const WebRtc_UWord8* payload_data,
WebRtc_UWord32 payload_size)
WebRtc_UWord32 payload_size,
const RTPVideoHeaderVP8& hdr_info)
: payload_data_(payload_data),
payload_size_(static_cast<int>(payload_size)),
part_info_(),
@ -54,8 +56,9 @@ RtpFormatVp8::RtpFormatVp8(const WebRtc_UWord8* payload_data,
first_fragment_(true),
vp8_header_bytes_(1),
aggr_mode_(aggr_modes_[kSloppy]),
balance_(bal_modes_[kSloppy]),
separate_first_(sep_first_modes_[kSloppy])
balance_(balance_modes_[kSloppy]),
separate_first_(separate_first_modes_[kSloppy]),
hdr_info_(hdr_info)
{
part_info_.VerifyAndAllocateFragmentationHeader(1);
part_info_.fragmentationLength[0] = payload_size;
@ -79,8 +82,7 @@ int RtpFormatVp8::CalcNextSize(int max_payload_len, int remaining_bytes,
// Balance payload sizes to produce (almost) equal size
// fragments.
// Number of fragments for remaining_bytes:
int num_frags = ceil(
static_cast<double>(remaining_bytes) / max_payload_len);
int num_frags = remaining_bytes / max_payload_len + 1;
// Number of bytes in this fragment:
return static_cast<int>(static_cast<double>(remaining_bytes)
/ num_frags + 0.5);
@ -98,8 +100,9 @@ int RtpFormatVp8::NextPacket(int max_payload_len, WebRtc_UWord8* buffer,
const int num_partitions = part_info_.fragmentationVectorSize;
int send_bytes = 0; // How much data to send in this packet.
bool split_payload = true; // Splitting of partitions is initially allowed.
int remaining_in_partition = part_info_.fragmentationOffset[part_ix_]
- payload_bytes_sent_ + part_info_.fragmentationLength[part_ix_];
int remaining_in_partition = part_info_.fragmentationOffset[part_ix_] -
payload_bytes_sent_ + part_info_.fragmentationLength[part_ix_] +
FirstHeaderExtraLength(); // Add header extra length to payload length.
int rem_payload_len = max_payload_len - vp8_header_bytes_;
while (int next_size = CalcNextSize(rem_payload_len, remaining_in_partition,
@ -137,9 +140,12 @@ int RtpFormatVp8::NextPacket(int max_payload_len, WebRtc_UWord8* buffer,
++part_ix_; // Advance to next partition.
}
send_bytes -= FirstHeaderExtraLength(); // Remove the extra length again.
assert(send_bytes > 0);
const bool end_of_fragment = (remaining_in_partition == 0);
// Write the payload header and the payload to buffer.
*bytes_to_send = WriteHeaderAndPayload(send_bytes, end_of_fragment, buffer);
*bytes_to_send = WriteHeaderAndPayload(send_bytes, end_of_fragment, buffer,
max_payload_len);
if (*bytes_to_send < 0)
{
return -1;
@ -150,46 +156,99 @@ int RtpFormatVp8::NextPacket(int max_payload_len, WebRtc_UWord8* buffer,
return 0;
}
int RtpFormatVp8::WriteHeaderAndPayload(int send_bytes,
int RtpFormatVp8::WriteHeaderAndPayload(int payload_bytes,
bool end_of_fragment,
WebRtc_UWord8* buffer)
WebRtc_UWord8* buffer,
int buffer_length)
{
// Write the VP8 payload header.
// 0 1 2 3 4 5 6 7
// +-+-+-+-+-+-+-+-+
// | RSV |I|N|FI |B|
// +-+-+-+-+-+-+-+-+
// 0 1 2
// 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | RSV |I|N|FI |B| PictureID (1 or 2 octets) |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
if (send_bytes < 0)
if (payload_bytes < 0)
{
return -1;
}
if (payload_bytes_sent_ + send_bytes > payload_size_)
if (payload_bytes_sent_ + payload_bytes > payload_size_)
{
return -1;
}
// PictureID always present in first packet
const int picture_id_present = beginning_;
// TODO(hlundin): must pipe this info from VP8 encoder
const int kNonrefFrame = 0;
buffer[0] = 0;
if (picture_id_present) buffer[0] |= (0x01 << 4); // I
if (kNonrefFrame) buffer[0] |= (0x01 << 3); // N
if (hdr_info_.nonReference) buffer[0] |= (0x01 << 3); // N
if (!first_fragment_) buffer[0] |= (0x01 << 2); // FI
if (!end_of_fragment) buffer[0] |= (0x01 << 1); // FI
if (beginning_) buffer[0] |= 0x01; // B
memcpy(&buffer[vp8_header_bytes_], &payload_data_[payload_bytes_sent_],
send_bytes);
int pic_id_len = WritePictureID(&buffer[vp8_header_bytes_],
buffer_length - vp8_header_bytes_);
if (pic_id_len < 0) return pic_id_len; // error
if (pic_id_len > 0) buffer[0] |= (0x01 << 4); // I
if (vp8_header_bytes_ + pic_id_len + payload_bytes > buffer_length)
{
return -1;
}
memcpy(&buffer[vp8_header_bytes_ + pic_id_len],
&payload_data_[payload_bytes_sent_], payload_bytes);
beginning_ = false; // next packet cannot be first packet in frame
// next packet starts new fragment if this ended one
first_fragment_ = end_of_fragment;
payload_bytes_sent_ += send_bytes;
payload_bytes_sent_ += payload_bytes;
// Return total length of written data.
return send_bytes + vp8_header_bytes_;
return payload_bytes + vp8_header_bytes_ + pic_id_len;
}
int RtpFormatVp8::WritePictureID(WebRtc_UWord8* buffer, int buffer_length) const
{
const WebRtc_UWord16 pic_id =
static_cast<WebRtc_UWord16> (hdr_info_.pictureId);
int picture_id_len = PictureIdLength();
if (picture_id_len > buffer_length) return -1; // error
if (picture_id_len == 2)
{
buffer[0] = 0x80 | ((pic_id >> 8) & 0x7F);
buffer[1] = pic_id & 0xFF;
}
else if (picture_id_len == 1)
{
buffer[0] = pic_id & 0x7F;
}
return picture_id_len;
}
int RtpFormatVp8::FirstHeaderExtraLength() const
{
if (!beginning_)
{
return 0;
}
int length = 0;
length += PictureIdLength();
return length;
}
int RtpFormatVp8::PictureIdLength() const
{
if (!beginning_ || hdr_info_.pictureId == kNoPictureId)
{
return 0;
}
if (hdr_info_.pictureId <= 0x7F)
{
return 1;
}
else
{
return 2;
}
}
} // namespace webrtc