1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/media/omx/OMXCodecDescriptorUtil.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,205 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this file,
1.7 + * You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "OMXCodecDescriptorUtil.h"
1.10 +
1.11 +namespace android {
1.12 +
1.13 +// The utility functions in this file concatenate two AVC/H.264 parameter sets,
1.14 +// sequence parameter set(SPS) and picture parameter set(PPS), into byte stream
1.15 +// format or construct AVC decoder config descriptor blob from them.
1.16 +//
1.17 +// * NAL unit defined in ISO/IEC 14496-10 7.3.1
1.18 +// * SPS defined ISO/IEC 14496-10 7.3.2.1.1
1.19 +// * PPS defined in ISO/IEC 14496-10 7.3.2.2
1.20 +//
1.21 +// Byte stream format:
1.22 +// Start code <0x00 0x00 0x00 0x01> (4 bytes)
1.23 +// --- (SPS) NAL unit ---
1.24 +// ... (3 bits)
1.25 +// NAL unit type <0x07> (5 bits)
1.26 +// SPS (3+ bytes)
1.27 +// Profile (1 byte)
1.28 +// Compatible profiles (1 byte)
1.29 +// Level (1 byte)
1.30 +// ...
1.31 +// --- End ---
1.32 +// Start code <0x00 0x00 0x00 0x01> (4 bytes)
1.33 +// --- (PPS) NAL unit ---
1.34 +// ... (3 bits)
1.35 +// NAL unit type <0x08> (5 bits)
1.36 +// PPS (1+ bytes)
1.37 +// ...
1.38 +// --- End ---
1.39 +//
1.40 +// Descriptor format: (defined in ISO/IEC 14496-15 5.2.4.1.1)
1.41 +// --- Header (5 bytes) ---
1.42 +// Version <0x01> (1 byte)
1.43 +// Profile (1 byte)
1.44 +// Compatible profiles (1 byte)
1.45 +// Level (1 byte)
1.46 +// Reserved <111111> (6 bits)
1.47 +// NAL length type (2 bits)
1.48 +// --- Parameter sets ---
1.49 +// Reserved <111> (3 bits)
1.50 +// Number of SPS (5 bits)
1.51 +// SPS (3+ bytes)
1.52 +// Length (2 bytes)
1.53 +// SPS NAL unit (1+ bytes)
1.54 +// ...
1.55 +// Number of PPS (1 byte)
1.56 +// PPS (3+ bytes)
1.57 +// Length (2 bytes)
1.58 +// PPS NAL unit (1+ bytes)
1.59 +// ...
1.60 +// --- End ---
1.61 +
1.62 +// NAL unit start code.
1.63 +static const uint8_t kNALUnitStartCode[] = { 0x00, 0x00, 0x00, 0x01 };
1.64 +
1.65 +// NAL unit types.
1.66 +enum {
1.67 + kNALUnitTypeSPS = 0x07, // Value for sequence parameter set.
1.68 + kNALUnitTypePPS = 0x08, // Value for picture parameter set.
1.69 + kNALUnitTypeBad = -1, // Malformed data.
1.70 +};
1.71 +
1.72 +// Sequence parameter set or picture parameter set.
1.73 +struct AVCParamSet {
1.74 + AVCParamSet(const uint8_t* aPtr, const size_t aSize)
1.75 + : mPtr(aPtr)
1.76 + , mSize(aSize)
1.77 + {
1.78 + MOZ_ASSERT(mPtr && mSize > 0);
1.79 + }
1.80 +
1.81 + size_t Size() {
1.82 + return mSize + 2; // 2 more bytes for length value.
1.83 + }
1.84 +
1.85 + // Append 2 bytes length value and NAL unit bitstream to aOutputBuf.
1.86 + void AppendTo(nsTArray<uint8_t>* aOutputBuf)
1.87 + {
1.88 + // 2 bytes length value.
1.89 + uint8_t size[] = {
1.90 + (mSize & 0xFF00) >> 8, // MSB.
1.91 + mSize & 0x00FF, // LSB.
1.92 + };
1.93 + aOutputBuf->AppendElements(size, sizeof(size));
1.94 +
1.95 + aOutputBuf->AppendElements(mPtr, mSize);
1.96 + }
1.97 +
1.98 + const uint8_t* mPtr; // Pointer to NAL unit.
1.99 + const size_t mSize; // NAL unit length in bytes.
1.100 +};
1.101 +
1.102 +// Convert SPS and PPS data into decoder config descriptor blob. The generated
1.103 +// blob will be appended to aOutputBuf.
1.104 +static status_t
1.105 +ConvertParamSetsToDescriptorBlob(sp<ABuffer>& aSPS, sp<ABuffer>& aPPS,
1.106 + nsTArray<uint8_t>* aOutputBuf)
1.107 +{
1.108 + // Strip start code in the input.
1.109 + AVCParamSet sps(aSPS->data() + sizeof(kNALUnitStartCode),
1.110 + aSPS->size() - sizeof(kNALUnitStartCode));
1.111 + AVCParamSet pps(aPPS->data() + sizeof(kNALUnitStartCode),
1.112 + aPPS->size() - sizeof(kNALUnitStartCode));
1.113 + size_t paramSetsSize = sps.Size() + pps.Size();
1.114 +
1.115 + // Profile/level info in SPS.
1.116 + uint8_t* info = aSPS->data() + 5;
1.117 +
1.118 + uint8_t header[] = {
1.119 + 0x01, // Version.
1.120 + info[0], // Profile.
1.121 + info[1], // Compatible profiles.
1.122 + info[2], // Level.
1.123 + 0xFF, // 6 bits reserved value <111111> + 2 bits NAL length type <11>
1.124 + };
1.125 +
1.126 + // Reserve 1 byte for number of SPS & another 1 for number of PPS.
1.127 + aOutputBuf->SetCapacity(sizeof(header) + paramSetsSize + 2);
1.128 + // Build the blob.
1.129 + aOutputBuf->AppendElements(header, sizeof(header)); // 5 bytes Header.
1.130 + aOutputBuf->AppendElement(0xE0 | 1); // 3 bits <111> + 5 bits number of SPS.
1.131 + sps.AppendTo(aOutputBuf); // SPS NALU data.
1.132 + aOutputBuf->AppendElement(1); // 1 byte number of PPS.
1.133 + pps.AppendTo(aOutputBuf); // PPS NALU data.
1.134 +
1.135 + return OK;
1.136 +}
1.137 +
1.138 +static int
1.139 +NALType(sp<ABuffer>& aBuffer)
1.140 +{
1.141 + if (aBuffer == nullptr) {
1.142 + return kNALUnitTypeBad;
1.143 + }
1.144 + // Start code?
1.145 + uint8_t* data = aBuffer->data();
1.146 + if (aBuffer->size() <= 4 ||
1.147 + memcmp(data, kNALUnitStartCode, sizeof(kNALUnitStartCode))) {
1.148 + return kNALUnitTypeBad;
1.149 + }
1.150 +
1.151 + return data[4] & 0x1F;
1.152 +}
1.153 +
1.154 +// Generate AVC/H.264 decoder config blob.
1.155 +// See MPEG4Writer::Track::makeAVCCodecSpecificData() and
1.156 +// MPEG4Writer::Track::writeAvccBox() implementation in libstagefright.
1.157 +status_t
1.158 +GenerateAVCDescriptorBlob(sp<AMessage>& aConfigData,
1.159 + nsTArray<uint8_t>* aOutputBuf,
1.160 + OMXVideoEncoder::BlobFormat aFormat)
1.161 +{
1.162 + // Search for parameter sets using key "csd-0" and "csd-1".
1.163 + char key[6] = "csd-";
1.164 + sp<ABuffer> sps;
1.165 + sp<ABuffer> pps;
1.166 + for (int i = 0; i < 2; i++) {
1.167 + snprintf(key + 4, 2, "%d", i);
1.168 + sp<ABuffer> paramSet;
1.169 + bool found = aConfigData->findBuffer(key, ¶mSet);
1.170 + int type = NALType(paramSet);
1.171 + bool valid = ((type == kNALUnitTypeSPS) || (type == kNALUnitTypePPS));
1.172 +
1.173 + MOZ_ASSERT(found && valid);
1.174 + if (!found || !valid) {
1.175 + return ERROR_MALFORMED;
1.176 + }
1.177 +
1.178 + switch (type) {
1.179 + case kNALUnitTypeSPS:
1.180 + sps = paramSet;
1.181 + break;
1.182 + case kNALUnitTypePPS:
1.183 + pps = paramSet;
1.184 + break;
1.185 + default:
1.186 + NS_NOTREACHED("Should not get here!");
1.187 + }
1.188 + }
1.189 +
1.190 + MOZ_ASSERT(sps != nullptr && pps != nullptr);
1.191 + if (sps == nullptr || pps == nullptr) {
1.192 + return ERROR_MALFORMED;
1.193 + }
1.194 +
1.195 + status_t result = OK;
1.196 + if (aFormat == OMXVideoEncoder::BlobFormat::AVC_NAL) {
1.197 + // SPS + PPS.
1.198 + aOutputBuf->AppendElements(sps->data(), sps->size());
1.199 + aOutputBuf->AppendElements(pps->data(), pps->size());
1.200 + return OK;
1.201 + } else {
1.202 + status_t result = ConvertParamSetsToDescriptorBlob(sps, pps, aOutputBuf);
1.203 + MOZ_ASSERT(result == OK);
1.204 + return result;
1.205 + }
1.206 +}
1.207 +
1.208 +} // namespace android
