| /* |
| * Copyright (c) 2015 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 "webrtc/modules/rtp_rtcp/source/rtp_format_vp9.h" |
| |
| #include <assert.h> |
| #include <string.h> |
| |
| #include <cmath> |
| |
| #include "webrtc/modules/rtp_rtcp/source/rtp_packet_to_send.h" |
| #include "webrtc/rtc_base/bitbuffer.h" |
| #include "webrtc/rtc_base/checks.h" |
| #include "webrtc/rtc_base/logging.h" |
| |
| #define RETURN_FALSE_ON_ERROR(x) \ |
| if (!(x)) { \ |
| return false; \ |
| } |
| |
| namespace webrtc { |
| namespace { |
| // Length of VP9 payload descriptors' fixed part. |
| const size_t kFixedPayloadDescriptorBytes = 1; |
| |
| const uint32_t kReservedBitValue0 = 0; |
| |
| uint8_t TemporalIdxField(const RTPVideoHeaderVP9& hdr, uint8_t def) { |
| return (hdr.temporal_idx == kNoTemporalIdx) ? def : hdr.temporal_idx; |
| } |
| |
| uint8_t SpatialIdxField(const RTPVideoHeaderVP9& hdr, uint8_t def) { |
| return (hdr.spatial_idx == kNoSpatialIdx) ? def : hdr.spatial_idx; |
| } |
| |
| int16_t Tl0PicIdxField(const RTPVideoHeaderVP9& hdr, uint8_t def) { |
| return (hdr.tl0_pic_idx == kNoTl0PicIdx) ? def : hdr.tl0_pic_idx; |
| } |
| |
| // Picture ID: |
| // |
| // +-+-+-+-+-+-+-+-+ |
| // I: |M| PICTURE ID | M:0 => picture id is 7 bits. |
| // +-+-+-+-+-+-+-+-+ M:1 => picture id is 15 bits. |
| // M: | EXTENDED PID | |
| // +-+-+-+-+-+-+-+-+ |
| // |
| size_t PictureIdLength(const RTPVideoHeaderVP9& hdr) { |
| if (hdr.picture_id == kNoPictureId) |
| return 0; |
| return (hdr.max_picture_id == kMaxOneBytePictureId) ? 1 : 2; |
| } |
| |
| bool PictureIdPresent(const RTPVideoHeaderVP9& hdr) { |
| return PictureIdLength(hdr) > 0; |
| } |
| |
| // Layer indices: |
| // |
| // Flexible mode (F=1): Non-flexible mode (F=0): |
| // |
| // +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ |
| // L: | T |U| S |D| | T |U| S |D| |
| // +-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+ |
| // | TL0PICIDX | |
| // +-+-+-+-+-+-+-+-+ |
| // |
| size_t LayerInfoLength(const RTPVideoHeaderVP9& hdr) { |
| if (hdr.temporal_idx == kNoTemporalIdx && |
| hdr.spatial_idx == kNoSpatialIdx) { |
| return 0; |
| } |
| return hdr.flexible_mode ? 1 : 2; |
| } |
| |
| bool LayerInfoPresent(const RTPVideoHeaderVP9& hdr) { |
| return LayerInfoLength(hdr) > 0; |
| } |
| |
| // 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. |
| // |
| size_t RefIndicesLength(const RTPVideoHeaderVP9& hdr) { |
| if (!hdr.inter_pic_predicted || !hdr.flexible_mode) |
| return 0; |
| |
| RTC_DCHECK_GT(hdr.num_ref_pics, 0U); |
| RTC_DCHECK_LE(hdr.num_ref_pics, kMaxVp9RefPics); |
| return hdr.num_ref_pics; |
| } |
| |
| // 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 . |
| // +-+-+-+-+-+-+-+-+ -| -| |
| // |
| size_t SsDataLength(const RTPVideoHeaderVP9& hdr) { |
| if (!hdr.ss_data_available) |
| return 0; |
| |
| RTC_DCHECK_GT(hdr.num_spatial_layers, 0U); |
| RTC_DCHECK_LE(hdr.num_spatial_layers, kMaxVp9NumberOfSpatialLayers); |
| RTC_DCHECK_LE(hdr.gof.num_frames_in_gof, kMaxVp9FramesInGof); |
| size_t length = 1; // V |
| if (hdr.spatial_layer_resolution_present) { |
| length += 4 * hdr.num_spatial_layers; // Y |
| } |
| if (hdr.gof.num_frames_in_gof > 0) { |
| ++length; // G |
| } |
| // N_G |
| length += hdr.gof.num_frames_in_gof; // T, U, R |
| for (size_t i = 0; i < hdr.gof.num_frames_in_gof; ++i) { |
| RTC_DCHECK_LE(hdr.gof.num_ref_pics[i], kMaxVp9RefPics); |
| length += hdr.gof.num_ref_pics[i]; // R times |
| } |
| return length; |
| } |
| |
| size_t PayloadDescriptorLengthMinusSsData(const RTPVideoHeaderVP9& hdr) { |
| return kFixedPayloadDescriptorBytes + PictureIdLength(hdr) + |
| LayerInfoLength(hdr) + RefIndicesLength(hdr); |
| } |
| |
| size_t PayloadDescriptorLength(const RTPVideoHeaderVP9& hdr) { |
| return PayloadDescriptorLengthMinusSsData(hdr) + SsDataLength(hdr); |
| } |
| |
| void QueuePacket(size_t start_pos, |
| size_t size, |
| bool layer_begin, |
| bool layer_end, |
| RtpPacketizerVp9::PacketInfoQueue* packets) { |
| RtpPacketizerVp9::PacketInfo packet_info; |
| packet_info.payload_start_pos = start_pos; |
| packet_info.size = size; |
| packet_info.layer_begin = layer_begin; |
| packet_info.layer_end = layer_end; |
| packets->push(packet_info); |
| } |
| |
| // Picture ID: |
| // |
| // +-+-+-+-+-+-+-+-+ |
| // I: |M| PICTURE ID | M:0 => picture id is 7 bits. |
| // +-+-+-+-+-+-+-+-+ M:1 => picture id is 15 bits. |
| // M: | EXTENDED PID | |
| // +-+-+-+-+-+-+-+-+ |
| // |
| bool WritePictureId(const RTPVideoHeaderVP9& vp9, |
| rtc::BitBufferWriter* writer) { |
| bool m_bit = (PictureIdLength(vp9) == 2); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(m_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.picture_id, m_bit ? 15 : 7)); |
| return true; |
| } |
| |
| // Layer indices: |
| // |
| // Flexible mode (F=1): |
| // |
| // +-+-+-+-+-+-+-+-+ |
| // L: | T |U| S |D| |
| // +-+-+-+-+-+-+-+-+ |
| // |
| bool WriteLayerInfoCommon(const RTPVideoHeaderVP9& vp9, |
| rtc::BitBufferWriter* writer) { |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(TemporalIdxField(vp9, 0), 3)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.temporal_up_switch ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(SpatialIdxField(vp9, 0), 3)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.inter_layer_predicted ? 1: 0, 1)); |
| return true; |
| } |
| |
| // Non-flexible mode (F=0): |
| // |
| // +-+-+-+-+-+-+-+-+ |
| // L: | T |U| S |D| |
| // +-+-+-+-+-+-+-+-+ |
| // | TL0PICIDX | |
| // +-+-+-+-+-+-+-+-+ |
| // |
| bool WriteLayerInfoNonFlexibleMode(const RTPVideoHeaderVP9& vp9, |
| rtc::BitBufferWriter* writer) { |
| RETURN_FALSE_ON_ERROR(writer->WriteUInt8(Tl0PicIdxField(vp9, 0))); |
| return true; |
| } |
| |
| bool WriteLayerInfo(const RTPVideoHeaderVP9& vp9, |
| rtc::BitBufferWriter* writer) { |
| if (!WriteLayerInfoCommon(vp9, writer)) |
| return false; |
| |
| if (vp9.flexible_mode) |
| return true; |
| |
| return WriteLayerInfoNonFlexibleMode(vp9, writer); |
| } |
| |
| // 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 WriteRefIndices(const RTPVideoHeaderVP9& vp9, |
| rtc::BitBufferWriter* writer) { |
| if (!PictureIdPresent(vp9) || |
| vp9.num_ref_pics == 0 || vp9.num_ref_pics > kMaxVp9RefPics) { |
| return false; |
| } |
| for (uint8_t i = 0; i < vp9.num_ref_pics; ++i) { |
| bool n_bit = !(i == vp9.num_ref_pics - 1); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.pid_diff[i], 7)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(n_bit ? 1 : 0, 1)); |
| } |
| 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 WriteSsData(const RTPVideoHeaderVP9& vp9, rtc::BitBufferWriter* writer) { |
| RTC_DCHECK_GT(vp9.num_spatial_layers, 0U); |
| RTC_DCHECK_LE(vp9.num_spatial_layers, kMaxVp9NumberOfSpatialLayers); |
| RTC_DCHECK_LE(vp9.gof.num_frames_in_gof, kMaxVp9FramesInGof); |
| bool g_bit = vp9.gof.num_frames_in_gof > 0; |
| |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.num_spatial_layers - 1, 3)); |
| RETURN_FALSE_ON_ERROR( |
| writer->WriteBits(vp9.spatial_layer_resolution_present ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(g_bit ? 1 : 0, 1)); // G |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(kReservedBitValue0, 3)); |
| |
| if (vp9.spatial_layer_resolution_present) { |
| for (size_t i = 0; i < vp9.num_spatial_layers; ++i) { |
| RETURN_FALSE_ON_ERROR(writer->WriteUInt16(vp9.width[i])); |
| RETURN_FALSE_ON_ERROR(writer->WriteUInt16(vp9.height[i])); |
| } |
| } |
| if (g_bit) { |
| RETURN_FALSE_ON_ERROR(writer->WriteUInt8(vp9.gof.num_frames_in_gof)); |
| } |
| for (size_t i = 0; i < vp9.gof.num_frames_in_gof; ++i) { |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.gof.temporal_idx[i], 3)); |
| RETURN_FALSE_ON_ERROR( |
| writer->WriteBits(vp9.gof.temporal_up_switch[i] ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(vp9.gof.num_ref_pics[i], 2)); |
| RETURN_FALSE_ON_ERROR(writer->WriteBits(kReservedBitValue0, 2)); |
| for (uint8_t r = 0; r < vp9.gof.num_ref_pics[i]; ++r) { |
| RETURN_FALSE_ON_ERROR(writer->WriteUInt8(vp9.gof.pid_diff[i][r])); |
| } |
| } |
| return true; |
| } |
| |
| // 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; |
| 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 |
| |
| RtpPacketizerVp9::RtpPacketizerVp9(const RTPVideoHeaderVP9& hdr, |
| size_t max_payload_length, |
| size_t last_packet_reduction_len) |
| : hdr_(hdr), |
| max_payload_length_(max_payload_length), |
| payload_(nullptr), |
| payload_size_(0), |
| last_packet_reduction_len_(last_packet_reduction_len) {} |
| |
| RtpPacketizerVp9::~RtpPacketizerVp9() { |
| } |
| |
| std::string RtpPacketizerVp9::ToString() { |
| return "RtpPacketizerVp9"; |
| } |
| |
| size_t RtpPacketizerVp9::SetPayloadData( |
| const uint8_t* payload, |
| size_t payload_size, |
| const RTPFragmentationHeader* fragmentation) { |
| payload_ = payload; |
| payload_size_ = payload_size; |
| GeneratePackets(); |
| return packets_.size(); |
| } |
| |
| // Splits payload in minimal number of roughly equal in size packets. |
| void RtpPacketizerVp9::GeneratePackets() { |
| if (max_payload_length_ < PayloadDescriptorLength(hdr_) + 1) { |
| LOG(LS_ERROR) << "Payload header and one payload byte won't fit in the " |
| "first packet."; |
| return; |
| } |
| if (max_payload_length_ < PayloadDescriptorLengthMinusSsData(hdr_) + 1 + |
| last_packet_reduction_len_) { |
| LOG(LS_ERROR) << "Payload header and one payload byte won't fit in the last" |
| " packet."; |
| return; |
| } |
| if (payload_size_ == 1 && |
| max_payload_length_ < |
| PayloadDescriptorLength(hdr_) + 1 + last_packet_reduction_len_) { |
| LOG(LS_ERROR) << "Can't fit header and payload into single packet, but " |
| "payload size is one: no way to generate packets with " |
| "nonzero payload."; |
| return; |
| } |
| |
| // Instead of making last packet smaller, we pretend that we must write |
| // additional data into it. We account for this virtual payload while |
| // calculating packets number and sizes. We also pretend that all packets |
| // headers are the same length and extra SS header data in the fits packet |
| // is also treated as a payload here. |
| |
| size_t ss_data_len = SsDataLength(hdr_); |
| // Payload, virtual payload and SS hdr data in the first packet together. |
| size_t total_bytes = ss_data_len + payload_size_ + last_packet_reduction_len_; |
| // Now all packets will have the same lenght of vp9 headers. |
| size_t per_packet_capacity = |
| max_payload_length_ - PayloadDescriptorLengthMinusSsData(hdr_); |
| // Integer division rounding up. |
| size_t num_packets = |
| (total_bytes + per_packet_capacity - 1) / per_packet_capacity; |
| // Average rounded down. |
| size_t per_packet_bytes = total_bytes / num_packets; |
| // Several last packets are 1 byte larger than the rest. |
| // i.e. if 14 bytes were split between 4 packets, it would be 3+3+4+4. |
| size_t num_larger_packets = total_bytes % num_packets; |
| size_t bytes_processed = 0; |
| size_t num_packets_left = num_packets; |
| while (bytes_processed < payload_size_) { |
| if (num_packets_left == num_larger_packets) |
| ++per_packet_bytes; |
| size_t packet_bytes = per_packet_bytes; |
| // First packet also has SS hdr data. |
| if (bytes_processed == 0) { |
| // Must write at least one byte of the real payload to the packet. |
| if (packet_bytes > ss_data_len) { |
| packet_bytes -= ss_data_len; |
| } else { |
| packet_bytes = 1; |
| } |
| } |
| size_t rem_bytes = payload_size_ - bytes_processed; |
| if (packet_bytes >= rem_bytes) { |
| // All remaining payload fits into this packet. |
| packet_bytes = rem_bytes; |
| // If this is the penultimate packet, leave at least 1 byte of payload for |
| // the last packet. |
| if (num_packets_left == 2) |
| --packet_bytes; |
| } |
| QueuePacket(bytes_processed, packet_bytes, bytes_processed == 0, |
| rem_bytes == packet_bytes, &packets_); |
| --num_packets_left; |
| bytes_processed += packet_bytes; |
| // Last packet should be smaller |
| RTC_DCHECK(num_packets_left > 0 || |
| per_packet_capacity >= |
| packet_bytes + last_packet_reduction_len_); |
| } |
| RTC_CHECK_EQ(bytes_processed, payload_size_); |
| } |
| |
| bool RtpPacketizerVp9::NextPacket(RtpPacketToSend* packet) { |
| RTC_DCHECK(packet); |
| if (packets_.empty()) { |
| return false; |
| } |
| PacketInfo packet_info = packets_.front(); |
| packets_.pop(); |
| |
| if (!WriteHeaderAndPayload(packet_info, packet, packets_.empty())) { |
| return false; |
| } |
| packet->SetMarker(packets_.empty() && |
| (hdr_.spatial_idx == kNoSpatialIdx || |
| hdr_.spatial_idx == hdr_.num_spatial_layers - 1)); |
| return true; |
| } |
| |
| // VP9 format: |
| // |
| // Payload descriptor for F = 1 (flexible mode) |
| // 0 1 2 3 4 5 6 7 |
| // +-+-+-+-+-+-+-+-+ |
| // |I|P|L|F|B|E|V|-| (REQUIRED) |
| // +-+-+-+-+-+-+-+-+ |
| // I: |M| PICTURE ID | (RECOMMENDED) |
| // +-+-+-+-+-+-+-+-+ |
| // M: | EXTENDED PID | (RECOMMENDED) |
| // +-+-+-+-+-+-+-+-+ |
| // L: | T |U| S |D| (CONDITIONALLY RECOMMENDED) |
| // +-+-+-+-+-+-+-+-+ -| |
| // P,F: | P_DIFF |N| (CONDITIONALLY RECOMMENDED) . up to 3 times |
| // +-+-+-+-+-+-+-+-+ -| |
| // V: | SS | |
| // | .. | |
| // +-+-+-+-+-+-+-+-+ |
| // |
| // Payload descriptor for F = 0 (non-flexible mode) |
| // 0 1 2 3 4 5 6 7 |
| // +-+-+-+-+-+-+-+-+ |
| // |I|P|L|F|B|E|V|-| (REQUIRED) |
| // +-+-+-+-+-+-+-+-+ |
| // I: |M| PICTURE ID | (RECOMMENDED) |
| // +-+-+-+-+-+-+-+-+ |
| // M: | EXTENDED PID | (RECOMMENDED) |
| // +-+-+-+-+-+-+-+-+ |
| // L: | T |U| S |D| (CONDITIONALLY RECOMMENDED) |
| // +-+-+-+-+-+-+-+-+ |
| // | TL0PICIDX | (CONDITIONALLY REQUIRED) |
| // +-+-+-+-+-+-+-+-+ |
| // V: | SS | |
| // | .. | |
| // +-+-+-+-+-+-+-+-+ |
| |
| bool RtpPacketizerVp9::WriteHeaderAndPayload(const PacketInfo& packet_info, |
| RtpPacketToSend* packet, |
| bool last) const { |
| uint8_t* buffer = packet->AllocatePayload( |
| last ? max_payload_length_ - last_packet_reduction_len_ |
| : max_payload_length_); |
| RTC_DCHECK(buffer); |
| size_t header_length; |
| if (!WriteHeader(packet_info, buffer, &header_length)) |
| return false; |
| |
| // Copy payload data. |
| memcpy(&buffer[header_length], |
| &payload_[packet_info.payload_start_pos], packet_info.size); |
| |
| packet->SetPayloadSize(header_length + packet_info.size); |
| return true; |
| } |
| |
| bool RtpPacketizerVp9::WriteHeader(const PacketInfo& packet_info, |
| uint8_t* buffer, |
| size_t* header_length) const { |
| // Required payload descriptor byte. |
| bool i_bit = PictureIdPresent(hdr_); |
| bool p_bit = hdr_.inter_pic_predicted; |
| bool l_bit = LayerInfoPresent(hdr_); |
| bool f_bit = hdr_.flexible_mode; |
| bool b_bit = packet_info.layer_begin; |
| bool e_bit = packet_info.layer_end; |
| bool v_bit = hdr_.ss_data_available && b_bit; |
| |
| rtc::BitBufferWriter writer(buffer, max_payload_length_); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(i_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(p_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(l_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(f_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(b_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(e_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(v_bit ? 1 : 0, 1)); |
| RETURN_FALSE_ON_ERROR(writer.WriteBits(kReservedBitValue0, 1)); |
| |
| // Add fields that are present. |
| if (i_bit && !WritePictureId(hdr_, &writer)) { |
| LOG(LS_ERROR) << "Failed writing VP9 picture id."; |
| return false; |
| } |
| if (l_bit && !WriteLayerInfo(hdr_, &writer)) { |
| LOG(LS_ERROR) << "Failed writing VP9 layer info."; |
| return false; |
| } |
| if (p_bit && f_bit && !WriteRefIndices(hdr_, &writer)) { |
| LOG(LS_ERROR) << "Failed writing VP9 ref indices."; |
| return false; |
| } |
| if (v_bit && !WriteSsData(hdr_, &writer)) { |
| LOG(LS_ERROR) << "Failed writing VP9 SS data."; |
| return false; |
| } |
| |
| size_t offset_bytes = 0; |
| size_t offset_bits = 0; |
| writer.GetCurrentOffset(&offset_bytes, &offset_bits); |
| assert(offset_bits == 0); |
| |
| *header_length = offset_bytes; |
| return true; |
| } |
| |
| bool RtpDepacketizerVp9::Parse(ParsedPayload* parsed_payload, |
| const uint8_t* payload, |
| size_t payload_length) { |
| assert(parsed_payload != nullptr); |
| if (payload_length == 0) { |
| LOG(LS_ERROR) << "Payload length is zero."; |
| return false; |
| } |
| |
| // Parse mandatory first byte of payload descriptor. |
| rtc::BitBuffer parser(payload, payload_length); |
| uint32_t i_bit, p_bit, l_bit, f_bit, b_bit, e_bit, v_bit; |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&i_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&p_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&l_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&f_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&b_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&e_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ReadBits(&v_bit, 1)); |
| RETURN_FALSE_ON_ERROR(parser.ConsumeBits(1)); |
| |
| // Parsed payload. |
| parsed_payload->type.Video.width = 0; |
| parsed_payload->type.Video.height = 0; |
| parsed_payload->type.Video.simulcastIdx = 0; |
| parsed_payload->type.Video.codec = kRtpVideoVp9; |
| |
| parsed_payload->frame_type = p_bit ? kVideoFrameDelta : kVideoFrameKey; |
| |
| RTPVideoHeaderVP9* vp9 = &parsed_payload->type.Video.codecHeader.VP9; |
| vp9->InitRTPVideoHeaderVP9(); |
| vp9->inter_pic_predicted = p_bit ? true : false; |
| vp9->flexible_mode = f_bit ? true : false; |
| vp9->beginning_of_frame = b_bit ? true : false; |
| vp9->end_of_frame = e_bit ? true : false; |
| vp9->ss_data_available = v_bit ? true : false; |
| vp9->spatial_idx = 0; |
| |
| // Parse fields that are present. |
| if (i_bit && !ParsePictureId(&parser, vp9)) { |
| LOG(LS_ERROR) << "Failed parsing VP9 picture id."; |
| return false; |
| } |
| if (l_bit && !ParseLayerInfo(&parser, vp9)) { |
| LOG(LS_ERROR) << "Failed parsing VP9 layer info."; |
| return false; |
| } |
| if (p_bit && f_bit && !ParseRefIndices(&parser, vp9)) { |
| LOG(LS_ERROR) << "Failed parsing VP9 ref indices."; |
| return false; |
| } |
| if (v_bit) { |
| if (!ParseSsData(&parser, vp9)) { |
| LOG(LS_ERROR) << "Failed parsing VP9 SS data."; |
| return false; |
| } |
| if (vp9->spatial_layer_resolution_present) { |
| // TODO(asapersson): Add support for spatial layers. |
| parsed_payload->type.Video.width = vp9->width[0]; |
| parsed_payload->type.Video.height = vp9->height[0]; |
| } |
| } |
| parsed_payload->type.Video.is_first_packet_in_frame = |
| b_bit && (!l_bit || !vp9->inter_layer_predicted); |
| |
| uint64_t rem_bits = parser.RemainingBitCount(); |
| assert(rem_bits % 8 == 0); |
| parsed_payload->payload_length = rem_bits / 8; |
| if (parsed_payload->payload_length == 0) { |
| LOG(LS_ERROR) << "Failed parsing VP9 payload data."; |
| return false; |
| } |
| parsed_payload->payload = |
| payload + payload_length - parsed_payload->payload_length; |
| |
| return true; |
| } |
| } // namespace webrtc |
