Better support for MP4A-LATM RTP disassembly. This used to fail if mNumSubFrames > 1 and the sub frames did not align with RTP packet boundaries.

Change-Id: I20e3b86f52b7f0f41663ffe8bc1f4db92280e884

4 files changed, 382 insertions, 20 deletions

diff --git a/media/libstagefright/rtsp/AMPEG4AudioAssembler.cpp b/media/libstagefright/rtsp/AMPEG4AudioAssembler.cpp
index b0d2c64..bbde516 100644
--- a/media/libstagefright/rtsp/AMPEG4AudioAssembler.cpp
+++ b/media/libstagefright/rtsp/AMPEG4AudioAssembler.cpp
@@ -18,18 +18,381 @@
 
 #include "ARTPSource.h"
 
+#include <media/stagefright/foundation/hexdump.h>
+#include <media/stagefright/foundation/ABitReader.h>
 #include <media/stagefright/foundation/ABuffer.h>
 #include <media/stagefright/foundation/ADebug.h>
 #include <media/stagefright/foundation/AMessage.h>
+#include <media/stagefright/MediaErrors.h>
+
+#include <ctype.h>
 
 namespace android {
 
-AMPEG4AudioAssembler::AMPEG4AudioAssembler(const sp<AMessage> &notify)
+static bool GetAttribute(const char *s, const char *key, AString *value) {
+    value->clear();
+
+    size_t keyLen = strlen(key);
+
+    for (;;) {
+        while (isspace(*s)) {
+            ++s;
+        }
+
+        const char *colonPos = strchr(s, ';');
+
+        size_t len =
+            (colonPos == NULL) ? strlen(s) : colonPos - s;
+
+        if (len >= keyLen + 1 && s[keyLen] == '=' && !strncmp(s, key, keyLen)) {
+            value->setTo(&s[keyLen + 1], len - keyLen - 1);
+            return true;
+        }
+
+        if (colonPos == NULL) {
+            return false;
+        }
+
+        s = colonPos + 1;
+    }
+}
+
+static sp<ABuffer> decodeHex(const AString &s) {
+    if ((s.size() % 2) != 0) {
+        return NULL;
+    }
+
+    size_t outLen = s.size() / 2;
+    sp<ABuffer> buffer = new ABuffer(outLen);
+    uint8_t *out = buffer->data();
+
+    uint8_t accum = 0;
+    for (size_t i = 0; i < s.size(); ++i) {
+        char c = s.c_str()[i];
+        unsigned value;
+        if (c >= '0' && c <= '9') {
+            value = c - '0';
+        } else if (c >= 'a' && c <= 'f') {
+            value = c - 'a' + 10;
+        } else if (c >= 'A' && c <= 'F') {
+            value = c - 'A' + 10;
+        } else {
+            return NULL;
+        }
+
+        accum = (accum << 4) | value;
+
+        if (i & 1) {
+            *out++ = accum;
+
+            accum = 0;
+        }
+    }
+
+    return buffer;
+}
+
+static status_t parseAudioObjectType(
+        ABitReader *bits, unsigned *audioObjectType) {
+    *audioObjectType = bits->getBits(5);
+    if ((*audioObjectType) == 31) {
+        *audioObjectType = 32 + bits->getBits(6);
+    }
+
+    return OK;
+}
+
+static status_t parseGASpecificConfig(
+        ABitReader *bits,
+        unsigned audioObjectType, unsigned channelConfiguration) {
+    unsigned frameLengthFlag = bits->getBits(1);
+    unsigned dependsOnCoreCoder = bits->getBits(1);
+    if (dependsOnCoreCoder) {
+        /* unsigned coreCoderDelay = */bits->getBits(1);
+    }
+    unsigned extensionFlag = bits->getBits(1);
+
+    if (!channelConfiguration) {
+        // program_config_element
+        return ERROR_UNSUPPORTED;  // XXX to be implemented
+    }
+
+    if (audioObjectType == 6 || audioObjectType == 20) {
+        /* unsigned layerNr = */bits->getBits(3);
+    }
+
+    if (extensionFlag) {
+        if (audioObjectType == 22) {
+            /* unsigned numOfSubFrame = */bits->getBits(5);
+            /* unsigned layerLength = */bits->getBits(11);
+        } else if (audioObjectType == 17 || audioObjectType == 19
+                || audioObjectType == 20 || audioObjectType == 23) {
+            /* unsigned aacSectionDataResilienceFlag = */bits->getBits(1);
+            /* unsigned aacScalefactorDataResilienceFlag = */bits->getBits(1);
+            /* unsigned aacSpectralDataResilienceFlag = */bits->getBits(1);
+        }
+
+        unsigned extensionFlag3 = bits->getBits(1);
+        CHECK_EQ(extensionFlag3, 0u);  // TBD in version 3
+    }
+
+    return OK;
+}
+
+static status_t parseAudioSpecificConfig(ABitReader *bits) {
+    unsigned audioObjectType;
+    CHECK_EQ(parseAudioObjectType(bits, &audioObjectType), (status_t)OK);
+
+    unsigned samplingFreqIndex = bits->getBits(4);
+    if (samplingFreqIndex == 0x0f) {
+        /* unsigned samplingFrequency = */bits->getBits(24);
+    }
+
+    unsigned channelConfiguration = bits->getBits(4);
+
+    unsigned extensionAudioObjectType = 0;
+    unsigned sbrPresent = 0;
+
+    if (audioObjectType == 5) {
+        extensionAudioObjectType = audioObjectType;
+        sbrPresent = 1;
+        unsigned extensionSamplingFreqIndex = bits->getBits(4);
+        if (extensionSamplingFreqIndex == 0x0f) {
+            /* unsigned extensionSamplingFrequency = */bits->getBits(24);
+        }
+        CHECK_EQ(parseAudioObjectType(bits, &audioObjectType), (status_t)OK);
+    }
+
+    CHECK((audioObjectType >= 1 && audioObjectType <= 4)
+        || (audioObjectType >= 6 && audioObjectType <= 7)
+        || audioObjectType == 17
+        || (audioObjectType >= 19 && audioObjectType <= 23));
+
+    CHECK_EQ(parseGASpecificConfig(
+                bits, audioObjectType, channelConfiguration), (status_t)OK);
+
+    if (audioObjectType == 17
+            || (audioObjectType >= 19 && audioObjectType <= 27)) {
+        unsigned epConfig = bits->getBits(2);
+        if (epConfig == 2 || epConfig == 3) {
+            // ErrorProtectionSpecificConfig
+            return ERROR_UNSUPPORTED;  // XXX to be implemented
+
+            if (epConfig == 3) {
+                unsigned directMapping = bits->getBits(1);
+                CHECK_EQ(directMapping, 1u);
+            }
+        }
+    }
+
+#if 0
+    // This is not supported here as the upper layers did not explicitly
+    // signal the length of AudioSpecificConfig.
+
+    if (extensionAudioObjectType != 5 && bits->numBitsLeft() >= 16) {
+        unsigned syncExtensionType = bits->getBits(11);
+        if (syncExtensionType == 0x2b7) {
+            CHECK_EQ(parseAudioObjectType(bits, &extensionAudioObjectType),
+                     (status_t)OK);
+
+            sbrPresent = bits->getBits(1);
+
+            if (sbrPresent == 1) {
+                unsigned extensionSamplingFreqIndex = bits->getBits(4);
+                if (extensionSamplingFreqIndex == 0x0f) {
+                    /* unsigned extensionSamplingFrequency = */bits->getBits(24);
+                }
+            }
+        }
+    }
+#endif
+
+    return OK;
+}
+
+static status_t parseStreamMuxConfig(
+        ABitReader *bits,
+        unsigned *numSubFrames,
+        unsigned *frameLengthType,
+        bool *otherDataPresent,
+        unsigned *otherDataLenBits) {
+    unsigned audioMuxVersion = bits->getBits(1);
+
+    unsigned audioMuxVersionA = 0;
+    if (audioMuxVersion == 1) {
+        audioMuxVersionA = bits->getBits(1);
+    }
+
+    CHECK_EQ(audioMuxVersionA, 0u);  // otherwise future spec
+
+    if (audioMuxVersion != 0) {
+        return ERROR_UNSUPPORTED;  // XXX to be implemented;
+    }
+    CHECK_EQ(audioMuxVersion, 0u);  // XXX to be implemented
+
+    unsigned allStreamsSameTimeFraming = bits->getBits(1);
+    CHECK_EQ(allStreamsSameTimeFraming, 1u);  // There's only one stream.
+
+    *numSubFrames = bits->getBits(6);
+    unsigned numProgram = bits->getBits(4);
+    CHECK_EQ(numProgram, 0u);  // disabled in RTP LATM
+
+    unsigned numLayer = bits->getBits(3);
+    CHECK_EQ(numLayer, 0u);  // disabled in RTP LATM
+
+    if (audioMuxVersion == 0) {
+        // AudioSpecificConfig
+        CHECK_EQ(parseAudioSpecificConfig(bits), (status_t)OK);
+    } else {
+        TRESPASS();  // XXX to be implemented
+    }
+
+    *frameLengthType = bits->getBits(3);
+    switch (*frameLengthType) {
+        case 0:
+        {
+            /* unsigned bufferFullness = */bits->getBits(8);
+
+            // The "coreFrameOffset" does not apply since there's only
+            // a single layer.
+            break;
+        }
+
+        case 1:
+        {
+            /* unsigned frameLength = */bits->getBits(9);
+            break;
+        }
+
+        case 3:
+        case 4:
+        case 5:
+        {
+            /* unsigned CELPframeLengthTableIndex = */bits->getBits(6);
+            break;
+        }
+
+        case 6:
+        case 7:
+        {
+            /* unsigned HVXCframeLengthTableIndex = */bits->getBits(1);
+            break;
+        }
+
+        default:
+            break;
+    }
+
+    *otherDataPresent = bits->getBits(1);
+    *otherDataLenBits = 0;
+    if (*otherDataPresent) {
+        if (audioMuxVersion == 1) {
+            TRESPASS();  // XXX to be implemented
+        } else {
+            *otherDataLenBits = 0;
+
+            unsigned otherDataLenEsc;
+            do {
+                (*otherDataLenBits) <<= 8;
+                otherDataLenEsc = bits->getBits(1);
+                unsigned otherDataLenTmp = bits->getBits(8);
+                (*otherDataLenBits) += otherDataLenTmp;
+            } while (otherDataLenEsc);
+        }
+    }
+
+    unsigned crcCheckPresent = bits->getBits(1);
+    if (crcCheckPresent) {
+        /* unsigned crcCheckSum = */bits->getBits(8);
+    }
+
+    return OK;
+}
+
+sp<ABuffer> AMPEG4AudioAssembler::removeLATMFraming(const sp<ABuffer> &buffer) {
+    CHECK(!mMuxConfigPresent);  // XXX to be implemented
+
+    sp<ABuffer> out = new ABuffer(buffer->size());
+    out->setRange(0, 0);
+
+    size_t offset = 0;
+    uint8_t *ptr = buffer->data();
+
+    for (size_t i = 0; i <= mNumSubFrames; ++i) {
+        // parse PayloadLengthInfo
+
+        unsigned payloadLength = 0;
+
+        switch (mFrameLengthType) {
+            case 0:
+            {
+                unsigned muxSlotLengthBytes = 0;
+                unsigned tmp;
+                do {
+                    CHECK_LT(offset, buffer->size());
+                    tmp = ptr[offset++];
+                    muxSlotLengthBytes += tmp;
+                } while (tmp == 0xff);
+
+                payloadLength = muxSlotLengthBytes;
+                break;
+            }
+
+            default:
+                TRESPASS();  // XXX to be implemented
+                break;
+        }
+
+        CHECK_LE(offset + payloadLength, buffer->size());
+
+        memcpy(out->data() + out->size(), &ptr[offset], payloadLength);
+        out->setRange(0, out->size() + payloadLength);
+
+        offset += payloadLength;
+
+        if (mOtherDataPresent) {
+            // We want to stay byte-aligned.
+
+            CHECK((mOtherDataLenBits % 8) == 0);
+            CHECK_LE(offset + (mOtherDataLenBits / 8), buffer->size());
+            offset += mOtherDataLenBits / 8;
+        }
+    }
+
+    CHECK_EQ(offset, buffer->size());
+
+    return out;
+}
+
+AMPEG4AudioAssembler::AMPEG4AudioAssembler(
+        const sp<AMessage> &notify, const AString &params)
     : mNotifyMsg(notify),
+      mMuxConfigPresent(false),
       mAccessUnitRTPTime(0),
       mNextExpectedSeqNoValid(false),
       mNextExpectedSeqNo(0),
       mAccessUnitDamaged(false) {
+    AString val;
+    if (!GetAttribute(params.c_str(), "cpresent", &val)) {
+        mMuxConfigPresent = true;
+    } else if (val == "0") {
+        mMuxConfigPresent = false;
+    } else {
+        CHECK(val == "1");
+        mMuxConfigPresent = true;
+    }
+
+    CHECK(GetAttribute(params.c_str(), "config", &val));
+
+    sp<ABuffer> config = decodeHex(val);
+    CHECK(config != NULL);
+
+    ABitReader bits(config->data(), config->size());
+    status_t err = parseStreamMuxConfig(
+            &bits, &mNumSubFrames, &mFrameLengthType,
+            &mOtherDataPresent, &mOtherDataLenBits);
+
+    CHECK_EQ(err, (status_t)NO_ERROR);
 }
 
 AMPEG4AudioAssembler::~AMPEG4AudioAssembler() {
@@ -108,13 +471,7 @@ void AMPEG4AudioAssembler::submitAccessUnit() {
     while (it != mPackets.end()) {
         const sp<ABuffer> &unit = *it;
 
-        size_t n = 0;
-        while (unit->data()[n] == 0xff) {
-            ++n;
-        }
-        ++n;
-
-        totalSize += unit->size() - n;
+        totalSize += unit->size();
         ++it;
     }
 
@@ -124,20 +481,13 @@ void AMPEG4AudioAssembler::submitAccessUnit() {
     while (it != mPackets.end()) {
         const sp<ABuffer> &unit = *it;
 
-        size_t n = 0;
-        while (unit->data()[n] == 0xff) {
-            ++n;
-        }
-        ++n;
-
         memcpy((uint8_t *)accessUnit->data() + offset,
-               unit->data() + n, unit->size() - n);
-
-        offset += unit->size() - n;
+               unit->data(), unit->size());
 
         ++it;
     }
 
+    accessUnit = removeLATMFraming(accessUnit);
     CopyTimes(accessUnit, *mPackets.begin());
 
 #if 0
diff --git a/media/libstagefright/rtsp/AMPEG4AudioAssembler.h b/media/libstagefright/rtsp/AMPEG4AudioAssembler.h
index bf9f204..9cef94c 100644
--- a/media/libstagefright/rtsp/AMPEG4AudioAssembler.h
+++ b/media/libstagefright/rtsp/AMPEG4AudioAssembler.h
@@ -27,9 +27,11 @@
 namespace android {
 
 struct AMessage;
+struct AString;
 
 struct AMPEG4AudioAssembler : public ARTPAssembler {
-    AMPEG4AudioAssembler(const sp<AMessage> &notify);
+    AMPEG4AudioAssembler(
+            const sp<AMessage> &notify, const AString &params);
 
 protected:
     virtual ~AMPEG4AudioAssembler();
@@ -40,6 +42,13 @@ protected:
 
 private:
     sp<AMessage> mNotifyMsg;
+
+    bool mMuxConfigPresent;
+    unsigned mNumSubFrames;
+    unsigned mFrameLengthType;
+    bool mOtherDataPresent;
+    unsigned mOtherDataLenBits;
+
     uint32_t mAccessUnitRTPTime;
     bool mNextExpectedSeqNoValid;
     uint32_t mNextExpectedSeqNo;
@@ -49,6 +58,8 @@ private:
     AssemblyStatus addPacket(const sp<ARTPSource> &source);
     void submitAccessUnit();
 
+    sp<ABuffer> removeLATMFraming(const sp<ABuffer> &buffer);
+
     DISALLOW_EVIL_CONSTRUCTORS(AMPEG4AudioAssembler);
 };
 
diff --git a/media/libstagefright/rtsp/ARTPSource.cpp b/media/libstagefright/rtsp/ARTPSource.cpp
index 2518264..5aae4e7 100644
--- a/media/libstagefright/rtsp/ARTPSource.cpp
+++ b/media/libstagefright/rtsp/ARTPSource.cpp
@@ -57,7 +57,7 @@ ARTPSource::ARTPSource(
         mAssembler = new AAVCAssembler(notify);
         mIssueFIRRequests = true;
     } else if (!strncmp(desc.c_str(), "MP4A-LATM/", 10)) {
-        mAssembler = new AMPEG4AudioAssembler(notify);
+        mAssembler = new AMPEG4AudioAssembler(notify, params);
     } else if (!strncmp(desc.c_str(), "H263-1998/", 10)
             || !strncmp(desc.c_str(), "H263-2000/", 10)) {
         mAssembler = new AH263Assembler(notify);
diff --git a/media/libstagefright/rtsp/ASessionDescription.cpp b/media/libstagefright/rtsp/ASessionDescription.cpp
index 880aa85..547fbab 100644
--- a/media/libstagefright/rtsp/ASessionDescription.cpp
+++ b/media/libstagefright/rtsp/ASessionDescription.cpp
@@ -53,7 +53,6 @@ bool ASessionDescription::parse(const void *data, size_t size) {
     mFormats.push(AString("[root]"));
 
     AString desc((const char *)data, size);
-    LOGI("%s", desc.c_str());
 
     size_t i = 0;
     for (;;) {
@@ -76,6 +75,8 @@ bool ASessionDescription::parse(const void *data, size_t size) {
             return false;
         }
 
+        LOGI("%s", line.c_str());
+
         switch (line.c_str()[0]) {
             case 'v':
             {