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webrtc_m130/modules/rtp_rtcp/source/video_rtp_depacketizer_vp9.cc
Danil Chapovalov 32fe4ef967 Move vp9 rtp depacketization to VideoRtpDepacketizerVp9 
Bug: webrtc:11152
Change-Id: I560d4cd62fabae093e3df592f0e7cc4001c10657
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/162420
Reviewed-by: Markus Handell <handellm@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30102}
2019-12-16 17:11:13 +00:00

288 lines
9.4 KiB
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/*
* Copyright (c) 2019 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "modules/rtp_rtcp/source/video_rtp_depacketizer_vp9.h"
#include <string.h>
#include "api/video/video_codec_constants.h"
#include "modules/rtp_rtcp/source/rtp_packet_to_send.h"
#include "modules/video_coding/codecs/interface/common_constants.h"
#include "rtc_base/bit_buffer.h"
#include "rtc_base/checks.h"
#include "rtc_base/logging.h"
#define RETURN_FALSE_ON_ERROR(x) \
if (!(x)) { \
return false; \
}
namespace webrtc {
namespace {
constexpr int kFailedToParse = 0;
// Picture ID:
//
// +-+-+-+-+-+-+-+-+
// I: |M| PICTURE ID | M:0 => picture id is 7 bits.
// +-+-+-+-+-+-+-+-+ M:1 => picture id is 15 bits.
// M: | EXTENDED PID |
// +-+-+-+-+-+-+-+-+
//
bool ParsePictureId(rtc::BitBuffer* parser, RTPVideoHeaderVP9* vp9) {
uint32_t picture_id;
uint32_t m_bit;
RETURN_FALSE_ON_ERROR(parser->ReadBits(&m_bit, 1));
if (m_bit) {
RETURN_FALSE_ON_ERROR(parser->ReadBits(&picture_id, 15));
vp9->max_picture_id = kMaxTwoBytePictureId;
} else {
RETURN_FALSE_ON_ERROR(parser->ReadBits(&picture_id, 7));
vp9->max_picture_id = kMaxOneBytePictureId;
}
vp9->picture_id = picture_id;
return true;
}
// Layer indices (flexible mode):
//
// +-+-+-+-+-+-+-+-+
// L: | T |U| S |D|
// +-+-+-+-+-+-+-+-+
//
bool ParseLayerInfoCommon(rtc::BitBuffer* parser, RTPVideoHeaderVP9* vp9) {
uint32_t t, u_bit, s, d_bit;
RETURN_FALSE_ON_ERROR(parser->ReadBits(&t, 3));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&u_bit, 1));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&s, 3));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&d_bit, 1));
vp9->temporal_idx = t;
vp9->temporal_up_switch = u_bit ? true : false;
if (s >= kMaxSpatialLayers)
return false;
vp9->spatial_idx = s;
vp9->inter_layer_predicted = d_bit ? true : false;
return true;
}
// Layer indices (non-flexible mode):
//
// +-+-+-+-+-+-+-+-+
// L: | T |U| S |D|
// +-+-+-+-+-+-+-+-+
// | TL0PICIDX |
// +-+-+-+-+-+-+-+-+
//
bool ParseLayerInfoNonFlexibleMode(rtc::BitBuffer* parser,
RTPVideoHeaderVP9* vp9) {
uint8_t tl0picidx;
RETURN_FALSE_ON_ERROR(parser->ReadUInt8(&tl0picidx));
vp9->tl0_pic_idx = tl0picidx;
return true;
}
bool ParseLayerInfo(rtc::BitBuffer* parser, RTPVideoHeaderVP9* vp9) {
if (!ParseLayerInfoCommon(parser, vp9))
return false;
if (vp9->flexible_mode)
return true;
return ParseLayerInfoNonFlexibleMode(parser, vp9);
}
// Reference indices:
//
// +-+-+-+-+-+-+-+-+ P=1,F=1: At least one reference index
// P,F: | P_DIFF |N| up to 3 times has to be specified.
// +-+-+-+-+-+-+-+-+ N=1: An additional P_DIFF follows
// current P_DIFF.
//
bool ParseRefIndices(rtc::BitBuffer* parser, RTPVideoHeaderVP9* vp9) {
if (vp9->picture_id == kNoPictureId)
return false;
vp9->num_ref_pics = 0;
uint32_t n_bit;
do {
if (vp9->num_ref_pics == kMaxVp9RefPics)
return false;
uint32_t p_diff;
RETURN_FALSE_ON_ERROR(parser->ReadBits(&p_diff, 7));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&n_bit, 1));
vp9->pid_diff[vp9->num_ref_pics] = p_diff;
uint32_t scaled_pid = vp9->picture_id;
if (p_diff > scaled_pid) {
// TODO(asapersson): Max should correspond to the picture id of last wrap.
scaled_pid += vp9->max_picture_id + 1;
}
vp9->ref_picture_id[vp9->num_ref_pics++] = scaled_pid - p_diff;
} while (n_bit);
return true;
}
// Scalability structure (SS).
//
// +-+-+-+-+-+-+-+-+
// V: | N_S |Y|G|-|-|-|
// +-+-+-+-+-+-+-+-+ -|
// Y: | WIDTH | (OPTIONAL) .
// + + .
// | | (OPTIONAL) .
// +-+-+-+-+-+-+-+-+ . N_S + 1 times
// | HEIGHT | (OPTIONAL) .
// + + .
// | | (OPTIONAL) .
// +-+-+-+-+-+-+-+-+ -|
// G: | N_G | (OPTIONAL)
// +-+-+-+-+-+-+-+-+ -|
// N_G: | T |U| R |-|-| (OPTIONAL) .
// +-+-+-+-+-+-+-+-+ -| . N_G times
// | P_DIFF | (OPTIONAL) . R times .
// +-+-+-+-+-+-+-+-+ -| -|
//
bool ParseSsData(rtc::BitBuffer* parser, RTPVideoHeaderVP9* vp9) {
uint32_t n_s, y_bit, g_bit;
RETURN_FALSE_ON_ERROR(parser->ReadBits(&n_s, 3));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&y_bit, 1));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&g_bit, 1));
RETURN_FALSE_ON_ERROR(parser->ConsumeBits(3));
vp9->num_spatial_layers = n_s + 1;
vp9->spatial_layer_resolution_present = y_bit ? true : false;
vp9->gof.num_frames_in_gof = 0;
if (y_bit) {
for (size_t i = 0; i < vp9->num_spatial_layers; ++i) {
RETURN_FALSE_ON_ERROR(parser->ReadUInt16(&vp9->width[i]));
RETURN_FALSE_ON_ERROR(parser->ReadUInt16(&vp9->height[i]));
}
}
if (g_bit) {
uint8_t n_g;
RETURN_FALSE_ON_ERROR(parser->ReadUInt8(&n_g));
vp9->gof.num_frames_in_gof = n_g;
}
for (size_t i = 0; i < vp9->gof.num_frames_in_gof; ++i) {
uint32_t t, u_bit, r;
RETURN_FALSE_ON_ERROR(parser->ReadBits(&t, 3));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&u_bit, 1));
RETURN_FALSE_ON_ERROR(parser->ReadBits(&r, 2));
RETURN_FALSE_ON_ERROR(parser->ConsumeBits(2));
vp9->gof.temporal_idx[i] = t;
vp9->gof.temporal_up_switch[i] = u_bit ? true : false;
vp9->gof.num_ref_pics[i] = r;
for (uint8_t p = 0; p < vp9->gof.num_ref_pics[i]; ++p) {
uint8_t p_diff;
RETURN_FALSE_ON_ERROR(parser->ReadUInt8(&p_diff));
vp9->gof.pid_diff[i][p] = p_diff;
}
}
return true;
}
} // namespace
absl::optional<VideoRtpDepacketizer::ParsedRtpPayload>
VideoRtpDepacketizerVp9::Parse(rtc::CopyOnWriteBuffer rtp_payload) {
rtc::ArrayView<const uint8_t> payload(rtp_payload.cdata(),
rtp_payload.size());
absl::optional<ParsedRtpPayload> result(absl::in_place);
int offset = ParseRtpPayload(payload, &result->video_header);
if (offset == kFailedToParse)
return absl::nullopt;
RTC_DCHECK_LT(offset, rtp_payload.size());
result->video_payload =
rtp_payload.Slice(offset, rtp_payload.size() - offset);
return result;
}
int VideoRtpDepacketizerVp9::ParseRtpPayload(
rtc::ArrayView<const uint8_t> rtp_payload,
RTPVideoHeader* video_header) {
RTC_DCHECK(video_header);
// Parse mandatory first byte of payload descriptor.
rtc::BitBuffer parser(rtp_payload.data(), rtp_payload.size());
uint8_t first_byte;
if (!parser.ReadUInt8(&first_byte)) {
RTC_LOG(LS_ERROR) << "Payload length is zero.";
return kFailedToParse;
}
bool i_bit = first_byte & 0b1000'0000; // PictureId present .
bool p_bit = first_byte & 0b0100'0000; // Inter-picture predicted.
bool l_bit = first_byte & 0b0010'0000; // Layer indices present.
bool f_bit = first_byte & 0b0001'0000; // Flexible mode.
bool b_bit = first_byte & 0b0000'1000; // Begins frame flag.
bool e_bit = first_byte & 0b0000'0100; // Ends frame flag.
bool v_bit = first_byte & 0b0000'0010; // Scalability structure present.
bool z_bit = first_byte & 0b0000'0001; // Not used for inter-layer prediction
// Parsed payload.
video_header->width = 0;
video_header->height = 0;
video_header->simulcastIdx = 0;
video_header->codec = kVideoCodecVP9;
video_header->frame_type =
p_bit ? VideoFrameType::kVideoFrameDelta : VideoFrameType::kVideoFrameKey;
auto& vp9_header =
video_header->video_type_header.emplace<RTPVideoHeaderVP9>();
vp9_header.InitRTPVideoHeaderVP9();
vp9_header.inter_pic_predicted = p_bit;
vp9_header.flexible_mode = f_bit;
vp9_header.beginning_of_frame = b_bit;
vp9_header.end_of_frame = e_bit;
vp9_header.ss_data_available = v_bit;
vp9_header.non_ref_for_inter_layer_pred = z_bit;
// Parse fields that are present.
if (i_bit && !ParsePictureId(&parser, &vp9_header)) {
RTC_LOG(LS_ERROR) << "Failed parsing VP9 picture id.";
return kFailedToParse;
}
if (l_bit && !ParseLayerInfo(&parser, &vp9_header)) {
RTC_LOG(LS_ERROR) << "Failed parsing VP9 layer info.";
return kFailedToParse;
}
if (p_bit && f_bit && !ParseRefIndices(&parser, &vp9_header)) {
RTC_LOG(LS_ERROR) << "Failed parsing VP9 ref indices.";
return kFailedToParse;
}
if (v_bit) {
if (!ParseSsData(&parser, &vp9_header)) {
RTC_LOG(LS_ERROR) << "Failed parsing VP9 SS data.";
return kFailedToParse;
}
if (vp9_header.spatial_layer_resolution_present) {
// TODO(asapersson): Add support for spatial layers.
video_header->width = vp9_header.width[0];
video_header->height = vp9_header.height[0];
}
}
video_header->is_first_packet_in_frame =
b_bit && (!l_bit || !vp9_header.inter_layer_predicted);
size_t byte_offset;
size_t bit_offset;
parser.GetCurrentOffset(&byte_offset, &bit_offset);
RTC_DCHECK_EQ(bit_offset, 0);
if (byte_offset == rtp_payload.size()) {
// Empty vp9 payload data.
return kFailedToParse;
}
return byte_offset;
}
} // namespace webrtc
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