v4l2_codec2: Move NALParser code to separate file.

This CL moves the simple NALParser to a dedicated file. The parser will
be expanded in a subsequent CL so moving the code in a separate CL will
make it easier to distinguish newly made changes.

Bug: 155138142
Test: arc.VideoEncodeAccel.h264_192p_i420_vm
Change-Id: I9691de7e610a4c9881c29dbdc337ae9d01668145

common/Android.bp

@@ -18,6 +18,7 @@ cc_library {
     srcs: [
         "EncodeHelpers.cpp",
         "FormatConverter.cpp",
+        "NalParser.cpp",
         "V4L2ComponentCommon.cpp",
         "VideoTypes.cpp",
     ],

common/EncodeHelpers.cpp

@@ -14,6 +14,8 @@
 #include <ui/GraphicBuffer.h>
 #include <utils/Log.h>
 
+#include <v4l2_codec2/common/NalParser.h>
+
 namespace android {
 
 media::VideoCodecProfile c2ProfileToVideoCodecProfile(C2Config::profile_t profile) {
@@ -160,32 +162,4 @@ void extractCSDInfo(std::unique_ptr<C2StreamInitDataInfo::output>* const csd, co
     std::memcpy((*csd)->m.value, tmpConfigData.get(), configDataLength);
 }
 
-NalParser::NalParser(const uint8_t* data, size_t length)
-      : mCurrNalDataPos(data), mDataEnd(data + length) {
-    mNextNalStartCodePos = findNextStartCodePos();
-}
-
-bool NalParser::locateNextNal() {
-    if (mNextNalStartCodePos == mDataEnd) return false;
-    mCurrNalDataPos = mNextNalStartCodePos + kNalStartCodeLength;  // skip start code.
-    mNextNalStartCodePos = findNextStartCodePos();
-    return true;
-}
-
-const uint8_t* NalParser::data() const {
-    return mCurrNalDataPos;
-}
-
-size_t NalParser::length() const {
-    if (mNextNalStartCodePos == mDataEnd) return mDataEnd - mCurrNalDataPos;
-    size_t length = mNextNalStartCodePos - mCurrNalDataPos;
-    // The start code could be 3 or 4 bytes, i.e., 0x000001 or 0x00000001.
-    return *(mNextNalStartCodePos - 1) == 0x00 ? length - 1 : length;
-}
-
-const uint8_t* NalParser::findNextStartCodePos() const {
-    return std::search(mCurrNalDataPos, mDataEnd, kNalStartCode,
-                       kNalStartCode + kNalStartCodeLength);
-}
-
 }  // namespace android

common/NalParser.cpp

+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include <v4l2_codec2/common/NalParser.h>
+
+#include <algorithm>
+
+namespace android {
+
+NalParser::NalParser(const uint8_t* data, size_t length)
+      : mCurrNalDataPos(data), mDataEnd(data + length) {
+    mNextNalStartCodePos = findNextStartCodePos();
+}
+
+bool NalParser::locateNextNal() {
+    if (mNextNalStartCodePos == mDataEnd) return false;
+    mCurrNalDataPos = mNextNalStartCodePos + kNalStartCodeLength;  // skip start code.
+    mNextNalStartCodePos = findNextStartCodePos();
+    return true;
+}
+
+const uint8_t* NalParser::data() const {
+    return mCurrNalDataPos;
+}
+
+size_t NalParser::length() const {
+    if (mNextNalStartCodePos == mDataEnd) return mDataEnd - mCurrNalDataPos;
+    size_t length = mNextNalStartCodePos - mCurrNalDataPos;
+    // The start code could be 3 or 4 bytes, i.e., 0x000001 or 0x00000001.
+    return *(mNextNalStartCodePos - 1) == 0x00 ? length - 1 : length;
+}
+
+const uint8_t* NalParser::findNextStartCodePos() const {
+    return std::search(mCurrNalDataPos, mDataEnd, kNalStartCode,
+                       kNalStartCode + kNalStartCodeLength);
+}
+
+}  // namespace android

common/include/v4l2_codec2/common/EncodeHelpers.h

@@ -52,38 +52,6 @@ android_ycbcr getGraphicBlockInfo(const C2ConstGraphicBlock& block);
 void extractCSDInfo(std::unique_ptr<C2StreamInitDataInfo::output>* const csd, const uint8_t* data,
                     size_t length);
 
-// Helper class to parse H264 NAL units from data.
-class NalParser {
-public:
-    NalParser(const uint8_t* data, size_t length);
-
-    // Locates the next NAL after |mNextNalStartCodePos|. If there is one, updates |mCurrNalDataPos|
-    // to the first byte of the NAL data (start code is not included), and |mNextNalStartCodePos| to
-    // the position of the next start code, and returns true.
-    // If there is no more NAL, returns false.
-    //
-    // Note: This method must be called prior to data() and length().
-    bool locateNextNal();
-
-    // Gets current NAL data (start code is not included).
-    const uint8_t* data() const;
-
-    // Gets the byte length of current NAL data (start code is not included).
-    size_t length() const;
-
-private:
-    const uint8_t* findNextStartCodePos() const;
-
-    // The byte pattern for the start of a H264 NAL unit.
-    const uint8_t kNalStartCode[3] = {0x00, 0x00, 0x01};
-    // The length in bytes of the NAL-unit start pattern.
-    const size_t kNalStartCodeLength = 3;
-
-    const uint8_t* mCurrNalDataPos;
-    const uint8_t* mDataEnd;
-    const uint8_t* mNextNalStartCodePos;
-};
-
 }  // namespace android
 
 #endif  // ANDROID_V4L2_CODEC2_COMMON_HELPERS_H

common/include/v4l2_codec2/common/NalParser.h

+// Copyright 2021 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ANDROID_V4L2_CODEC2_COMMON_NALPARSER_H
+#define ANDROID_V4L2_CODEC2_COMMON_NALPARSER_H
+
+#include <stdint.h>
+
+namespace android {
+
+// Helper class to parse H264 NAL units from data.
+class NalParser {
+public:
+    NalParser(const uint8_t* data, size_t length);
+
+    // Locates the next NAL after |mNextNalStartCodePos|. If there is one, updates |mCurrNalDataPos|
+    // to the first byte of the NAL data (start code is not included), and |mNextNalStartCodePos| to
+    // the position of the next start code, and returns true.
+    // If there is no more NAL, returns false.
+    //
+    // Note: This method must be called prior to data() and length().
+    bool locateNextNal();
+
+    // Gets current NAL data (start code is not included).
+    const uint8_t* data() const;
+
+    // Gets the byte length of current NAL data (start code is not included).
+    size_t length() const;
+
+private:
+    const uint8_t* findNextStartCodePos() const;
+
+    // The byte pattern for the start of a H264 NAL unit.
+    const uint8_t kNalStartCode[3] = {0x00, 0x00, 0x01};
+    // The length in bytes of the NAL-unit start pattern.
+    const size_t kNalStartCodeLength = 3;
+
+    const uint8_t* mCurrNalDataPos;
+    const uint8_t* mDataEnd;
+    const uint8_t* mNextNalStartCodePos;
+};
+
+}  // namespace android
+
+#endif  // ANDROID_V4L2_CODEC2_COMMON_NALPARSER_H