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h264.cc: handle both kinds of ffmpeg extradata.

This commit is contained in:
Scott Lamb 2016-01-10 21:28:07 -08:00
parent 29054d42a0
commit 798f1db039
3 changed files with 106 additions and 68 deletions
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51
src/h264-test.cc
View File

@ -43,15 +43,32 @@ DECLARE_bool(alsologtostderr);
namespace moonfire_nvr {
namespace {
const uint8_t kTestInput[] = {
const uint8_t kAnnexBTestInput[] = {
0x00, 0x00, 0x00, 0x01, 0x67, 0x4d, 0x00, 0x1f, 0x9a, 0x66, 0x02, 0x80,
0x2d, 0xff, 0x35, 0x01, 0x01, 0x01, 0x40, 0x00, 0x00, 0xfa, 0x00, 0x00,
0x1d, 0x4c, 0x01, 0x00, 0x00, 0x00, 0x01, 0x68, 0xee, 0x3c, 0x80};
const uint8_t kAvcDecoderConfigTestInput[] = {
0x01, 0x4d, 0x00, 0x1f, 0xff, 0xe1, 0x00, 0x17, 0x67, 0x4d,
0x00, 0x1f, 0x9a, 0x66, 0x02, 0x80, 0x2d, 0xff, 0x35, 0x01,
0x01, 0x01, 0x40, 0x00, 0x00, 0xfa, 0x00, 0x00, 0x1d, 0x4c,
0x01, 0x01, 0x00, 0x04, 0x68, 0xee, 0x3c, 0x80};
const char kTestOutput[] =
"00 00 00 84 61 76 63 31 00 00 00 00 00 00 00 01 "
"00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
"05 00 02 d0 00 48 00 00 00 48 00 00 00 00 00 00 "
"00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
"00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
"00 00 00 18 ff ff 00 00 00 2e 61 76 63 43 01 4d "
"00 1f ff e1 00 17 67 4d 00 1f 9a 66 02 80 2d ff "
"35 01 01 01 40 00 00 fa 00 00 1d 4c 01 01 00 04 "
"68 ee 3c 80";
TEST(H264Test, DecodeOnly) {
std::vector<std::string> nal_units_hexed;
re2::StringPiece test_input(reinterpret_cast<const char *>(kTestInput),
sizeof(kTestInput));
re2::StringPiece test_input(reinterpret_cast<const char *>(kAnnexBTestInput),
sizeof(kAnnexBTestInput));
internal::NalUnitFunction fn = [&nal_units_hexed](re2::StringPiece nal_unit) {
nal_units_hexed.push_back(ToHex(nal_unit));
return IterationControl::kContinue;
@ -65,20 +82,22 @@ TEST(H264Test, DecodeOnly) {
"68 ee 3c 80"));
}
TEST(H264Test, SampleData) {
const char kTestOutput[] =
"00 00 00 84 61 76 63 31 00 00 00 00 00 00 00 01 "
"00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
"05 00 02 d0 00 48 00 00 00 48 00 00 00 00 00 00 "
"00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
"00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 "
"00 00 00 18 ff ff 00 00 00 2e 61 76 63 43 01 4d "
"00 1f ff e1 00 17 67 4d 00 1f 9a 66 02 80 2d ff "
"35 01 01 01 40 00 00 fa 00 00 1d 4c 01 01 00 04 "
"68 ee 3c 80";
TEST(H264Test, SampleDataFromAnnexBExtraData) {
re2::StringPiece test_input(reinterpret_cast<const char *>(kAnnexBTestInput),
sizeof(kAnnexBTestInput));
std::string sample_entry;
std::string error_message;
ASSERT_TRUE(
GetH264SampleEntry(test_input, 1280, 720, &sample_entry, &error_message))
<< error_message;
re2::StringPiece test_input(reinterpret_cast<const char *>(kTestInput),
sizeof(kTestInput));
EXPECT_EQ(kTestOutput, ToHex(sample_entry));
}
TEST(H264Test, SampleDataFromAvcDecoderConfigExtraData) {
re2::StringPiece test_input(
reinterpret_cast<const char *>(kAvcDecoderConfigTestInput),
sizeof(kAvcDecoderConfigTestInput));
std::string sample_entry;
std::string error_message;
ASSERT_TRUE(

100
src/h264.cc
View File

@ -48,8 +48,8 @@ const int kNalUnitPicParameterSet = 8;
// Parse sequence parameter set and picture parameter set from ffmpeg's
// "extra_data".
bool ParseExtraData(re2::StringPiece extra_data, re2::StringPiece *sps,
re2::StringPiece *pps, std::string *error_message) {
bool ParseAnnexBExtraData(re2::StringPiece extradata, re2::StringPiece *sps,
re2::StringPiece *pps, std::string *error_message) {
bool ok = true;
internal::NalUnitFunction fn = [&ok, sps, pps,
error_message](re2::StringPiece nal_unit) {
@ -70,7 +70,7 @@ bool ParseExtraData(re2::StringPiece extra_data, re2::StringPiece *sps,
}
return IterationControl::kContinue;
};
if (!internal::DecodeH264AnnexB(extra_data, fn, error_message) || !ok) {
if (!internal::DecodeH264AnnexB(extradata, fn, error_message) || !ok) {
return false;
}
if (sps->empty() || pps->empty()) {
@ -92,7 +92,8 @@ bool DecodeH264AnnexB(re2::StringPiece data, NalUnitFunction process_nal_unit,
static const RE2 kStartCode("(\\x00{2,}\\x01)");
if (!RE2::Consume(&data, kStartCode)) {
*error_message = "stream does not start with Annex B start code";
*error_message =
StrCat("stream does not start with Annex B start code: ", ToHex(data));
return false;
}
@ -124,18 +125,27 @@ bool DecodeH264AnnexB(re2::StringPiece data, NalUnitFunction process_nal_unit,
} // namespace internal
bool GetH264SampleEntry(re2::StringPiece extra_data, uint16_t width,
bool GetH264SampleEntry(re2::StringPiece extradata, uint16_t width,
uint16_t height, std::string *out,
std::string *error_message) {
uint32_t avcc_len;
re2::StringPiece sps;
re2::StringPiece pps;
if (!ParseExtraData(extra_data, &sps, &pps, error_message)) {
return false;
if (extradata.starts_with(re2::StringPiece("\x00\x00\x00\x01", 4)) ||
extradata.starts_with(re2::StringPiece("\x00\x00\x01", 3))) {
// ffmpeg supplied "extradata" in Annex B format.
if (!ParseAnnexBExtraData(extradata, &sps, &pps, error_message)) {
return false;
}
// This magic value is checked at the end.
avcc_len = 19 + sps.size() + pps.size();
} else {
// Assume "extradata" holds an AVCDecoderConfiguration.
avcc_len = 8 + extradata.size();
}
// These match the size of all fields below.
// Don't panic; they're verified at the end.
uint32_t avcc_len = 19 + sps.size() + pps.size();
// This magic value is also checked at the end.
uint32_t avc1_len = 86 + avcc_len;
out->clear();
@ -167,42 +177,48 @@ bool GetH264SampleEntry(re2::StringPiece extra_data, uint16_t width,
AppendU32(avcc_len, out); // length
out->append("avcC"); // type
// AVCDecoderConfiguration, ISO/IEC 14496-15 section 5.2.4.1.
// The beginning of the AVCDecoderConfiguration takes a few values from
// the SPS (ISO/IEC 14496-10 section 7.3.2.1.1). One caveat: that section
// defines the syntax in terms of RBSP, not NAL. The difference is the
// escaping of 00 00 01 and 00 00 02; see notes about
// "emulation_prevention_three_byte" in ISO/IEC 14496-10 section 7.4.
// It looks like 00 is not a valid value of profile_idc, so this distinction
// shouldn't be relevant here. And ffmpeg seems to ignore it.
out->push_back(1); // configurationVersion
out->push_back(sps[1]); // profile_idc -> AVCProfileIndication
out->push_back(sps[2]); // ...misc bits... -> profile_compatibility
out->push_back(sps[3]); // level_idc -> AVCLevelIndication
if (!sps.empty() && !pps.empty()) {
// Create the AVCDecoderConfiguration, ISO/IEC 14496-15 section 5.2.4.1.
// The beginning of the AVCDecoderConfiguration takes a few values from
// the SPS (ISO/IEC 14496-10 section 7.3.2.1.1). One caveat: that section
// defines the syntax in terms of RBSP, not NAL. The difference is the
// escaping of 00 00 01 and 00 00 02; see notes about
// "emulation_prevention_three_byte" in ISO/IEC 14496-10 section 7.4.
// It looks like 00 is not a valid value of profile_idc, so this distinction
// shouldn't be relevant here. And ffmpeg seems to ignore it.
out->push_back(1); // configurationVersion
out->push_back(sps[1]); // profile_idc -> AVCProfileIndication
out->push_back(sps[2]); // ...misc bits... -> profile_compatibility
out->push_back(sps[3]); // level_idc -> AVCLevelIndication
// Hardcode lengthSizeMinusOne to 3. This needs to match what ffmpeg uses
// when generating AVCParameterSamples (ISO/IEC 14496-15 section 5.3.2).
// There doesn't seem to be a clean way to get this from ffmpeg, but it's
// always 3.
out->push_back(static_cast<char>(0xff));
// Hardcode lengthSizeMinusOne to 3. This needs to match what ffmpeg uses
// when generating AVCParameterSamples (ISO/IEC 14496-15 section 5.3.2).
// There doesn't seem to be a clean way to get this from ffmpeg, but it's
// always 3.
out->push_back(static_cast<char>(0xff));
// Only support one SPS and PPS.
// ffmpeg's ff_isom_write_avcc has the same limitation, so it's probably fine.
// This next byte is a reserved 0b111 + a 5-bit # of SPSs (1).
out->push_back(static_cast<char>(0xe1));
AppendU16(sps.size(), out);
out->append(sps.data(), sps.size());
out->push_back(1); // # of PPSs.
AppendU16(pps.size(), out);
out->append(pps.data(), pps.size());
// Only support one SPS and PPS.
// ffmpeg's ff_isom_write_avcc has the same limitation, so it's probably
// fine. This next byte is a reserved 0b111 + a 5-bit # of SPSs (1).
out->push_back(static_cast<char>(0xe1));
AppendU16(sps.size(), out);
out->append(sps.data(), sps.size());
out->push_back(1); // # of PPSs.
AppendU16(pps.size(), out);
out->append(pps.data(), pps.size());
if (out->size() - avcc_len_pos != avcc_len) {
*error_message =
StrCat("internal error: anticipated AVCConfigurationBox length ",
avcc_len, ", but was actually ", out->size() - avcc_len_pos,
"; sps length ", sps.size(), ", pps length ", pps.size());
return false;
if (out->size() - avcc_len_pos != avcc_len) {
*error_message =
StrCat("internal error: anticipated AVCConfigurationBox length ",
avcc_len, ", but was actually ", out->size() - avcc_len_pos,
"; sps length ", sps.size(), ", pps length ", pps.size());
return false;
}
} else {
out->append(extradata.data(), extradata.size());
}
if (out->size() - avc1_len_pos != avc1_len) {
*error_message =
StrCat("internal error: anticipated AVCSampleEntry length ", avc1_len,

23
src/h264.h
View File

@ -31,15 +31,18 @@
// h264.h: H.264 decoding. For the most part, Moonfire NVR does not try to
// understand the video codec. There's one exception. It must construct the
// .mp4 sample description table, and for AVC, this includes the ISO/IEC
// 14496-15 section 5.2.4.1 AVCDecoderConfigurationRecord. ffmpeg supplies (as
// "extra data") an ISO/IEC 14496-10 Annex B byte stream containing SPS
// (sequence parameter set) and PPS (picture parameter set) NAL units from
// which this can be constructed.
// 14496-15 section 5.2.4.1 AVCDecoderConfigurationRecord.
//
// ffmpeg of course also has logic for converting "extra data" to the
// AVCDecoderConfigurationRecord, but unfortunately it is not exposed except
// through ffmpeg's own generated .mp4 file. Extracting just this part of
// their .mp4 files would be more trouble than it's worth.
// When handling a RTSP input source, ffmpeg supplies as "extradata" an
// ISO/IEC 14496-10 Annex B byte stream containing SPS (sequence parameter
// set) and PPS (picture parameter set) NAL units from which this can be
// constructed. ffmpeg of course also has logic for converting "extradata"
// to the AVCDecoderConfigurationRecord, but unfortunately it is not exposed
// except through ffmpeg's own generated .mp4 file. Extracting just this part
// of their .mp4 files would be more trouble than it's worth.
//
// Just to make things interesting, when handling a .mp4 file, ffmpeg supplies
// as "extradata" an AVCDecoderConfiguration.
#ifndef MOONFIRE_NVR_H264_H
#define MOONFIRE_NVR_H264_H
@ -71,9 +74,9 @@ bool DecodeH264AnnexB(re2::StringPiece data, NalUnitFunction process_nal_unit,
} // namespace
// Gets a H.264 sample entry (AVCSampleEntry, which extends
// VisualSampleEntry), given the "extra_data", width, and height supplied by
// VisualSampleEntry), given the "extradata", width, and height supplied by
// ffmpeg.
bool GetH264SampleEntry(re2::StringPiece extra_data, uint16_t width,
bool GetH264SampleEntry(re2::StringPiece extradata, uint16_t width,
uint16_t height, std::string *out,
std::string *error_message);