| /* | 
 |  *  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 "common_video/h264/sps_parser.h" | 
 |  | 
 | #include "common_video/h264/h264_common.h" | 
 | #include "rtc_base/arraysize.h" | 
 | #include "rtc_base/bit_buffer.h" | 
 | #include "rtc_base/buffer.h" | 
 | #include "test/gtest.h" | 
 |  | 
 | namespace webrtc { | 
 |  | 
 | // Example SPS can be generated with ffmpeg. Here's an example set of commands, | 
 | // runnable on OS X: | 
 | // 1) Generate a video, from the camera: | 
 | // ffmpeg -f avfoundation -i "0" -video_size 640x360 camera.mov | 
 | // | 
 | // 2) Scale the video to the desired size: | 
 | // ffmpeg -i camera.mov -vf scale=640x360 scaled.mov | 
 | // | 
 | // 3) Get just the H.264 bitstream in AnnexB: | 
 | // ffmpeg -i scaled.mov -vcodec copy -vbsf h264_mp4toannexb -an out.h264 | 
 | // | 
 | // 4) Open out.h264 and find the SPS, generally everything between the first | 
 | // two start codes (0 0 0 1 or 0 0 1). The first byte should be 0x67, | 
 | // which should be stripped out before being passed to the parser. | 
 |  | 
 | static const size_t kSpsBufferMaxSize = 256; | 
 |  | 
 | // Generates a fake SPS with basically everything empty but the width/height. | 
 | // Pass in a buffer of at least kSpsBufferMaxSize. | 
 | // The fake SPS that this generates also always has at least one emulation byte | 
 | // at offset 2, since the first two bytes are always 0, and has a 0x3 as the | 
 | // level_idc, to make sure the parser doesn't eat all 0x3 bytes. | 
 | void GenerateFakeSps(uint16_t width, | 
 |                      uint16_t height, | 
 |                      int id, | 
 |                      uint32_t log2_max_frame_num_minus4, | 
 |                      uint32_t log2_max_pic_order_cnt_lsb_minus4, | 
 |                      rtc::Buffer* out_buffer) { | 
 |   uint8_t rbsp[kSpsBufferMaxSize] = {0}; | 
 |   rtc::BitBufferWriter writer(rbsp, kSpsBufferMaxSize); | 
 |   // Profile byte. | 
 |   writer.WriteUInt8(0); | 
 |   // Constraint sets and reserved zero bits. | 
 |   writer.WriteUInt8(0); | 
 |   // level_idc. | 
 |   writer.WriteUInt8(0x3u); | 
 |   // seq_paramter_set_id. | 
 |   writer.WriteExponentialGolomb(id); | 
 |   // Profile is not special, so we skip all the chroma format settings. | 
 |  | 
 |   // Now some bit magic. | 
 |   // log2_max_frame_num_minus4: ue(v). | 
 |   writer.WriteExponentialGolomb(log2_max_frame_num_minus4); | 
 |   // pic_order_cnt_type: ue(v). 0 is the type we want. | 
 |   writer.WriteExponentialGolomb(0); | 
 |   // log2_max_pic_order_cnt_lsb_minus4: ue(v). 0 is fine. | 
 |   writer.WriteExponentialGolomb(log2_max_pic_order_cnt_lsb_minus4); | 
 |   // max_num_ref_frames: ue(v). 0 is fine. | 
 |   writer.WriteExponentialGolomb(0); | 
 |   // gaps_in_frame_num_value_allowed_flag: u(1). | 
 |   writer.WriteBits(0, 1); | 
 |   // Next are width/height. First, calculate the mbs/map_units versions. | 
 |   uint16_t width_in_mbs_minus1 = (width + 15) / 16 - 1; | 
 |  | 
 |   // For the height, we're going to define frame_mbs_only_flag, so we need to | 
 |   // divide by 2. See the parser for the full calculation. | 
 |   uint16_t height_in_map_units_minus1 = ((height + 15) / 16 - 1) / 2; | 
 |   // Write each as ue(v). | 
 |   writer.WriteExponentialGolomb(width_in_mbs_minus1); | 
 |   writer.WriteExponentialGolomb(height_in_map_units_minus1); | 
 |   // frame_mbs_only_flag: u(1). Needs to be false. | 
 |   writer.WriteBits(0, 1); | 
 |   // mb_adaptive_frame_field_flag: u(1). | 
 |   writer.WriteBits(0, 1); | 
 |   // direct_8x8_inferene_flag: u(1). | 
 |   writer.WriteBits(0, 1); | 
 |   // frame_cropping_flag: u(1). 1, so we can supply crop. | 
 |   writer.WriteBits(1, 1); | 
 |   // Now we write the left/right/top/bottom crop. For simplicity, we'll put all | 
 |   // the crop at the left/top. | 
 |   // We picked a 4:2:0 format, so the crops are 1/2 the pixel crop values. | 
 |   // Left/right. | 
 |   writer.WriteExponentialGolomb(((16 - (width % 16)) % 16) / 2); | 
 |   writer.WriteExponentialGolomb(0); | 
 |   // Top/bottom. | 
 |   writer.WriteExponentialGolomb(((16 - (height % 16)) % 16) / 2); | 
 |   writer.WriteExponentialGolomb(0); | 
 |  | 
 |   // vui_parameters_present_flag: u(1) | 
 |   writer.WriteBits(0, 1); | 
 |  | 
 |   // Get the number of bytes written (including the last partial byte). | 
 |   size_t byte_count, bit_offset; | 
 |   writer.GetCurrentOffset(&byte_count, &bit_offset); | 
 |   if (bit_offset > 0) { | 
 |     byte_count++; | 
 |   } | 
 |  | 
 |   out_buffer->Clear(); | 
 |   H264::WriteRbsp(rbsp, byte_count, out_buffer); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestSampleSPSHdLandscape) { | 
 |   // SPS for a 1280x720 camera capture from ffmpeg on osx. Contains | 
 |   // emulation bytes but no cropping. | 
 |   const uint8_t buffer[] = {0x7A, 0x00, 0x1F, 0xBC, 0xD9, 0x40, 0x50, 0x05, | 
 |                             0xBA, 0x10, 0x00, 0x00, 0x03, 0x00, 0xC0, 0x00, | 
 |                             0x00, 0x2A, 0xE0, 0xF1, 0x83, 0x19, 0x60}; | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer, arraysize(buffer)); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(1280u, sps->width); | 
 |   EXPECT_EQ(720u, sps->height); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestSampleSPSVgaLandscape) { | 
 |   // SPS for a 640x360 camera capture from ffmpeg on osx. Contains emulation | 
 |   // bytes and cropping (360 isn't divisible by 16). | 
 |   const uint8_t buffer[] = {0x7A, 0x00, 0x1E, 0xBC, 0xD9, 0x40, 0xA0, 0x2F, | 
 |                             0xF8, 0x98, 0x40, 0x00, 0x00, 0x03, 0x01, 0x80, | 
 |                             0x00, 0x00, 0x56, 0x83, 0xC5, 0x8B, 0x65, 0x80}; | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer, arraysize(buffer)); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(640u, sps->width); | 
 |   EXPECT_EQ(360u, sps->height); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestSampleSPSWeirdResolution) { | 
 |   // SPS for a 200x400 camera capture from ffmpeg on osx. Horizontal and | 
 |   // veritcal crop (neither dimension is divisible by 16). | 
 |   const uint8_t buffer[] = {0x7A, 0x00, 0x0D, 0xBC, 0xD9, 0x43, 0x43, 0x3E, | 
 |                             0x5E, 0x10, 0x00, 0x00, 0x03, 0x00, 0x60, 0x00, | 
 |                             0x00, 0x15, 0xA0, 0xF1, 0x42, 0x99, 0x60}; | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer, arraysize(buffer)); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(200u, sps->width); | 
 |   EXPECT_EQ(400u, sps->height); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestSyntheticSPSQvgaLandscape) { | 
 |   rtc::Buffer buffer; | 
 |   GenerateFakeSps(320u, 180u, 1, 0, 0, &buffer); | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer.data(), buffer.size()); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(320u, sps->width); | 
 |   EXPECT_EQ(180u, sps->height); | 
 |   EXPECT_EQ(1u, sps->id); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestSyntheticSPSWeirdResolution) { | 
 |   rtc::Buffer buffer; | 
 |   GenerateFakeSps(156u, 122u, 2, 0, 0, &buffer); | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer.data(), buffer.size()); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(156u, sps->width); | 
 |   EXPECT_EQ(122u, sps->height); | 
 |   EXPECT_EQ(2u, sps->id); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestSampleSPSWithScalingLists) { | 
 |   // SPS from a 1920x1080 video. Contains scaling lists (and vertical cropping). | 
 |   const uint8_t buffer[] = {0x64, 0x00, 0x2a, 0xad, 0x84, 0x01, 0x0c, 0x20, | 
 |                             0x08, 0x61, 0x00, 0x43, 0x08, 0x02, 0x18, 0x40, | 
 |                             0x10, 0xc2, 0x00, 0x84, 0x3b, 0x50, 0x3c, 0x01, | 
 |                             0x13, 0xf2, 0xcd, 0xc0, 0x40, 0x40, 0x50, 0x00, | 
 |                             0x00, 0x00, 0x10, 0x00, 0x00, 0x01, 0xe8, 0x40}; | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer, arraysize(buffer)); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(1920u, sps->width); | 
 |   EXPECT_EQ(1080u, sps->height); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestLog2MaxFrameNumMinus4) { | 
 |   rtc::Buffer buffer; | 
 |   GenerateFakeSps(320u, 180u, 1, 0, 0, &buffer); | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer.data(), buffer.size()); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(320u, sps->width); | 
 |   EXPECT_EQ(180u, sps->height); | 
 |   EXPECT_EQ(1u, sps->id); | 
 |   EXPECT_EQ(4u, sps->log2_max_frame_num); | 
 |  | 
 |   GenerateFakeSps(320u, 180u, 1, 12, 0, &buffer); | 
 |   sps = SpsParser::ParseSps(buffer.data(), buffer.size()); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(320u, sps->width); | 
 |   EXPECT_EQ(180u, sps->height); | 
 |   EXPECT_EQ(1u, sps->id); | 
 |   EXPECT_EQ(16u, sps->log2_max_frame_num); | 
 |  | 
 |   GenerateFakeSps(320u, 180u, 1, 13, 0, &buffer); | 
 |   EXPECT_FALSE(SpsParser::ParseSps(buffer.data(), buffer.size())); | 
 | } | 
 |  | 
 | TEST(H264SpsParserTest, TestLog2MaxPicOrderCntMinus4) { | 
 |   rtc::Buffer buffer; | 
 |   GenerateFakeSps(320u, 180u, 1, 0, 0, &buffer); | 
 |   absl::optional<SpsParser::SpsState> sps = | 
 |       SpsParser::ParseSps(buffer.data(), buffer.size()); | 
 |   ASSERT_TRUE(sps.has_value()); | 
 |   EXPECT_EQ(320u, sps->width); | 
 |   EXPECT_EQ(180u, sps->height); | 
 |   EXPECT_EQ(1u, sps->id); | 
 |   EXPECT_EQ(4u, sps->log2_max_pic_order_cnt_lsb); | 
 |  | 
 |   GenerateFakeSps(320u, 180u, 1, 0, 12, &buffer); | 
 |   EXPECT_TRUE(static_cast<bool>( | 
 |       sps = SpsParser::ParseSps(buffer.data(), buffer.size()))); | 
 |   EXPECT_EQ(320u, sps->width); | 
 |   EXPECT_EQ(180u, sps->height); | 
 |   EXPECT_EQ(1u, sps->id); | 
 |   EXPECT_EQ(16u, sps->log2_max_pic_order_cnt_lsb); | 
 |  | 
 |   GenerateFakeSps(320u, 180u, 1, 0, 13, &buffer); | 
 |   EXPECT_FALSE(SpsParser::ParseSps(buffer.data(), buffer.size())); | 
 | } | 
 |  | 
 | }  // namespace webrtc |