media/libstagefright/MediaCodecList.cpp

/*
 * Copyright 2012, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

//#define LOG_NDEBUG 0
#define LOG_TAG "MediaCodecList"
#include <utils/Log.h>

#include "MediaCodecListOverrides.h"

#include <binder/IServiceManager.h>

#include <media/IMediaCodecList.h>
#include <media/IMediaPlayerService.h>
#include <media/MediaCodecInfo.h>

#include <media/stagefright/foundation/ADebug.h>
#include <media/stagefright/foundation/AMessage.h>
#include <media/stagefright/MediaCodecList.h>
#include <media/stagefright/MediaErrors.h>
#include <media/stagefright/OMXClient.h>
#include <media/stagefright/OMXCodec.h>

#include <sys/stat.h>
#include <utils/threads.h>

#include <libexpat/expat.h>

namespace android {

static Mutex sInitMutex;

static MediaCodecList *gCodecList = NULL;

static const char *kProfilingResults = "/data/misc/media/media_codecs_profiling_results.xml";

static bool parseBoolean(const char *s) {
    if (!strcasecmp(s, "true") || !strcasecmp(s, "yes") || !strcasecmp(s, "y")) {
        return true;
    }
    char *end;
    unsigned long res = strtoul(s, &end, 10);
    return *s != '\0' && *end == '\0' && res > 0;
}

// static
sp<IMediaCodecList> MediaCodecList::sCodecList;

// static
sp<IMediaCodecList> MediaCodecList::getLocalInstance() {
    bool profilingNeeded = false;
    KeyedVector<AString, CodecSettings> updates;
    Vector<sp<MediaCodecInfo>> infos;

    {
        Mutex::Autolock autoLock(sInitMutex);

        if (gCodecList == NULL) {
            gCodecList = new MediaCodecList;
            if (gCodecList->initCheck() == OK) {
                sCodecList = gCodecList;

                struct stat s;
                if (stat(kProfilingResults, &s) == -1) {
                    // profiling results doesn't existed
                    profilingNeeded = true;
                    for (size_t i = 0; i < gCodecList->countCodecs(); ++i) {
                        infos.push_back(gCodecList->getCodecInfo(i));
                    }
                }
            } else {
                // failure to initialize may be temporary. retry on next call.
                delete gCodecList;
                gCodecList = NULL;
            }
        }
    }

    if (profilingNeeded) {
        profileCodecs(infos, &updates);
    }

    {
        Mutex::Autolock autoLock(sInitMutex);
        if (updates.size() > 0) {
            gCodecList->updateDetailsForMultipleCodecs(updates);
        }

        return sCodecList;
    }
}

static Mutex sRemoteInitMutex;

sp<IMediaCodecList> MediaCodecList::sRemoteList;

sp<MediaCodecList::BinderDeathObserver> MediaCodecList::sBinderDeathObserver;

void MediaCodecList::BinderDeathObserver::binderDied(const wp<IBinder> &who __unused) {
    Mutex::Autolock _l(sRemoteInitMutex);
    sRemoteList.clear();
    sBinderDeathObserver.clear();
}

// static
sp<IMediaCodecList> MediaCodecList::getInstance() {
    Mutex::Autolock _l(sRemoteInitMutex);
    if (sRemoteList == NULL) {
        sp<IBinder> binder =
            defaultServiceManager()->getService(String16("media.player"));
        sp<IMediaPlayerService> service =
            interface_cast<IMediaPlayerService>(binder);
        if (service.get() != NULL) {
            sRemoteList = service->getCodecList();
            if (sRemoteList != NULL) {
                sBinderDeathObserver = new BinderDeathObserver();
                binder->linkToDeath(sBinderDeathObserver.get());
            }
        }
        if (sRemoteList == NULL) {
            // if failed to get remote list, create local list
            sRemoteList = getLocalInstance();
        }
    }
    return sRemoteList;
}

MediaCodecList::MediaCodecList()
    : mInitCheck(NO_INIT),
      mUpdate(false),
      mGlobalSettings(new AMessage()) {
    parseTopLevelXMLFile("/etc/media_codecs.xml");
    parseTopLevelXMLFile(kProfilingResults, true/* ignore_errors */);
}

void MediaCodecList::updateDetailsForMultipleCodecs(
        const KeyedVector<AString, CodecSettings>& updates) {
    if (updates.size() == 0) {
        return;
    }

    exportResultsToXML(kProfilingResults, updates);

    for (size_t i = 0; i < updates.size(); ++i) {
        applyCodecSettings(updates.keyAt(i), updates.valueAt(i), &mCodecInfos);
    }
}

void MediaCodecList::parseTopLevelXMLFile(const char *codecs_xml, bool ignore_errors) {
    // get href_base
    char *href_base_end = strrchr(codecs_xml, '/');
    if (href_base_end != NULL) {
        mHrefBase = AString(codecs_xml, href_base_end - codecs_xml + 1);
    }

    mInitCheck = OK; // keeping this here for safety
    mCurrentSection = SECTION_TOPLEVEL;
    mDepth = 0;

    OMXClient client;
    mInitCheck = client.connect();
    if (mInitCheck != OK) {
        return;  // this may fail if IMediaPlayerService is not available.
    }
    mOMX = client.interface();
    parseXMLFile(codecs_xml);
    mOMX.clear();

    if (mInitCheck != OK) {
        if (ignore_errors) {
            mInitCheck = OK;
            return;
        }
        mCodecInfos.clear();
        return;
    }

    for (size_t i = mCodecInfos.size(); i-- > 0;) {
        const MediaCodecInfo &info = *mCodecInfos.itemAt(i).get();
        if (info.mCaps.size() == 0) {
            // No types supported by this component???
            ALOGW("Component %s does not support any type of media?",
                  info.mName.c_str());

            mCodecInfos.removeAt(i);
#if LOG_NDEBUG == 0
        } else {
            for (size_t type_ix = 0; type_ix < info.mCaps.size(); ++type_ix) {
                AString mime = info.mCaps.keyAt(type_ix);
                const sp<MediaCodecInfo::Capabilities> &caps = info.mCaps.valueAt(type_ix);

                ALOGV("%s codec info for %s: %s", info.mName.c_str(), mime.c_str(),
                        caps->getDetails()->debugString().c_str());
                ALOGV("    flags=%d", caps->getFlags());
                {
                    Vector<uint32_t> colorFormats;
                    caps->getSupportedColorFormats(&colorFormats);
                    AString nice;
                    for (size_t ix = 0; ix < colorFormats.size(); ix++) {
                        if (ix > 0) {
                            nice.append(", ");
                        }
                        nice.append(colorFormats.itemAt(ix));
                    }
                    ALOGV("    colors=[%s]", nice.c_str());
                }
                {
                    Vector<MediaCodecInfo::ProfileLevel> profileLevels;
                    caps->getSupportedProfileLevels(&profileLevels);
                    AString nice;
                    for (size_t ix = 0; ix < profileLevels.size(); ix++) {
                        if (ix > 0) {
                            nice.append(", ");
                        }
                        const MediaCodecInfo::ProfileLevel &pl =
                            profileLevels.itemAt(ix);
                        nice.append(pl.mProfile);
                        nice.append("/");
                        nice.append(pl.mLevel);
                    }
                    ALOGV("    levels=[%s]", nice.c_str());
                }
                {
                    AString quirks;
                    for (size_t ix = 0; ix < info.mQuirks.size(); ix++) {
                        if (ix > 0) {
                            quirks.append(", ");
                        }
                        quirks.append(info.mQuirks[ix]);
                    }
                    ALOGV("    quirks=[%s]", quirks.c_str());
                }
            }
#endif
        }
    }

#if 0
    for (size_t i = 0; i < mCodecInfos.size(); ++i) {
        const CodecInfo &info = mCodecInfos.itemAt(i);

        AString line = info.mName;
        line.append(" supports ");
        for (size_t j = 0; j < mTypes.size(); ++j) {
            uint32_t value = mTypes.valueAt(j);

            if (info.mTypes & (1ul << value)) {
                line.append(mTypes.keyAt(j));
                line.append(" ");
            }
        }

        ALOGI("%s", line.c_str());
    }
#endif
}

MediaCodecList::~MediaCodecList() {
}

status_t MediaCodecList::initCheck() const {
    return mInitCheck;
}

void MediaCodecList::parseXMLFile(const char *path) {
    FILE *file = fopen(path, "r");

    if (file == NULL) {
        ALOGW("unable to open media codecs configuration xml file: %s", path);
        mInitCheck = NAME_NOT_FOUND;
        return;
    }

    XML_Parser parser = ::XML_ParserCreate(NULL);
    CHECK(parser != NULL);

    ::XML_SetUserData(parser, this);
    ::XML_SetElementHandler(
            parser, StartElementHandlerWrapper, EndElementHandlerWrapper);

    const int BUFF_SIZE = 512;
    while (mInitCheck == OK) {
        void *buff = ::XML_GetBuffer(parser, BUFF_SIZE);
        if (buff == NULL) {
            ALOGE("failed in call to XML_GetBuffer()");
            mInitCheck = UNKNOWN_ERROR;
            break;
        }

        int bytes_read = ::fread(buff, 1, BUFF_SIZE, file);
        if (bytes_read < 0) {
            ALOGE("failed in call to read");
            mInitCheck = ERROR_IO;
            break;
        }

        XML_Status status = ::XML_ParseBuffer(parser, bytes_read, bytes_read == 0);
        if (status != XML_STATUS_OK) {
            ALOGE("malformed (%s)", ::XML_ErrorString(::XML_GetErrorCode(parser)));
            mInitCheck = ERROR_MALFORMED;
            break;
        }

        if (bytes_read == 0) {
            break;
        }
    }

    ::XML_ParserFree(parser);

    fclose(file);
    file = NULL;
}

// static
void MediaCodecList::StartElementHandlerWrapper(
        void *me, const char *name, const char **attrs) {
    static_cast<MediaCodecList *>(me)->startElementHandler(name, attrs);
}

// static
void MediaCodecList::EndElementHandlerWrapper(void *me, const char *name) {
    static_cast<MediaCodecList *>(me)->endElementHandler(name);
}

status_t MediaCodecList::includeXMLFile(const char **attrs) {
    const char *href = NULL;
    size_t i = 0;
    while (attrs[i] != NULL) {
        if (!strcmp(attrs[i], "href")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            href = attrs[i + 1];
            ++i;
        } else {
            return -EINVAL;
        }
        ++i;
    }

    // For security reasons and for simplicity, file names can only contain
    // [a-zA-Z0-9_.] and must start with  media_codecs_ and end with .xml
    for (i = 0; href[i] != '\0'; i++) {
        if (href[i] == '.' || href[i] == '_' ||
                (href[i] >= '0' && href[i] <= '9') ||
                (href[i] >= 'A' && href[i] <= 'Z') ||
                (href[i] >= 'a' && href[i] <= 'z')) {
            continue;
        }
        ALOGE("invalid include file name: %s", href);
        return -EINVAL;
    }

    AString filename = href;
    if (!filename.startsWith("media_codecs_") ||
        !filename.endsWith(".xml")) {
        ALOGE("invalid include file name: %s", href);
        return -EINVAL;
    }
    filename.insert(mHrefBase, 0);

    parseXMLFile(filename.c_str());
    return mInitCheck;
}

void MediaCodecList::startElementHandler(
        const char *name, const char **attrs) {
    if (mInitCheck != OK) {
        return;
    }

    bool inType = true;

    if (!strcmp(name, "Include")) {
        mInitCheck = includeXMLFile(attrs);
        if (mInitCheck == OK) {
            mPastSections.push(mCurrentSection);
            mCurrentSection = SECTION_INCLUDE;
        }
        ++mDepth;
        return;
    }

    switch (mCurrentSection) {
        case SECTION_TOPLEVEL:
        {
            if (!strcmp(name, "Decoders")) {
                mCurrentSection = SECTION_DECODERS;
            } else if (!strcmp(name, "Encoders")) {
                mCurrentSection = SECTION_ENCODERS;
            } else if (!strcmp(name, "Settings")) {
                mCurrentSection = SECTION_SETTINGS;
            }
            break;
        }

        case SECTION_SETTINGS:
        {
            if (!strcmp(name, "Setting")) {
                mInitCheck = addSettingFromAttributes(attrs);
            }
            break;
        }

        case SECTION_DECODERS:
        {
            if (!strcmp(name, "MediaCodec")) {
                mInitCheck =
                    addMediaCodecFromAttributes(false /* encoder */, attrs);

                mCurrentSection = SECTION_DECODER;
            }
            break;
        }

        case SECTION_ENCODERS:
        {
            if (!strcmp(name, "MediaCodec")) {
                mInitCheck =
                    addMediaCodecFromAttributes(true /* encoder */, attrs);

                mCurrentSection = SECTION_ENCODER;
            }
            break;
        }

        case SECTION_DECODER:
        case SECTION_ENCODER:
        {
            if (!strcmp(name, "Quirk")) {
                mInitCheck = addQuirk(attrs);
            } else if (!strcmp(name, "Type")) {
                mInitCheck = addTypeFromAttributes(attrs);
                mCurrentSection =
                    (mCurrentSection == SECTION_DECODER
                            ? SECTION_DECODER_TYPE : SECTION_ENCODER_TYPE);
            }
        }
        inType = false;
        // fall through

        case SECTION_DECODER_TYPE:
        case SECTION_ENCODER_TYPE:
        {
            // ignore limits and features specified outside of type
            bool outside = !inType && !mCurrentInfo->mHasSoleMime;
            if (outside && (!strcmp(name, "Limit") || !strcmp(name, "Feature"))) {
                ALOGW("ignoring %s specified outside of a Type", name);
            } else if (!strcmp(name, "Limit")) {
                mInitCheck = addLimit(attrs);
            } else if (!strcmp(name, "Feature")) {
                mInitCheck = addFeature(attrs);
            }
            break;
        }

        default:
            break;
    }

    ++mDepth;
}

void MediaCodecList::endElementHandler(const char *name) {
    if (mInitCheck != OK) {
        return;
    }

    switch (mCurrentSection) {
        case SECTION_SETTINGS:
        {
            if (!strcmp(name, "Settings")) {
                mCurrentSection = SECTION_TOPLEVEL;
            }
            break;
        }

        case SECTION_DECODERS:
        {
            if (!strcmp(name, "Decoders")) {
                mCurrentSection = SECTION_TOPLEVEL;
            }
            break;
        }

        case SECTION_ENCODERS:
        {
            if (!strcmp(name, "Encoders")) {
                mCurrentSection = SECTION_TOPLEVEL;
            }
            break;
        }

        case SECTION_DECODER_TYPE:
        case SECTION_ENCODER_TYPE:
        {
            if (!strcmp(name, "Type")) {
                mCurrentSection =
                    (mCurrentSection == SECTION_DECODER_TYPE
                            ? SECTION_DECODER : SECTION_ENCODER);

                mCurrentInfo->complete();
            }
            break;
        }

        case SECTION_DECODER:
        {
            if (!strcmp(name, "MediaCodec")) {
                mCurrentSection = SECTION_DECODERS;
                mCurrentInfo->complete();
                mCurrentInfo = NULL;
            }
            break;
        }

        case SECTION_ENCODER:
        {
            if (!strcmp(name, "MediaCodec")) {
                mCurrentSection = SECTION_ENCODERS;
                mCurrentInfo->complete();;
                mCurrentInfo = NULL;
            }
            break;
        }

        case SECTION_INCLUDE:
        {
            if (!strcmp(name, "Include") && mPastSections.size() > 0) {
                mCurrentSection = mPastSections.top();
                mPastSections.pop();
            }
            break;
        }

        default:
            break;
    }

    --mDepth;
}

status_t MediaCodecList::addSettingFromAttributes(const char **attrs) {
    const char *name = NULL;
    const char *value = NULL;
    const char *update = NULL;

    size_t i = 0;
    while (attrs[i] != NULL) {
        if (!strcmp(attrs[i], "name")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            name = attrs[i + 1];
            ++i;
        } else if (!strcmp(attrs[i], "value")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            value = attrs[i + 1];
            ++i;
        } else if (!strcmp(attrs[i], "update")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            update = attrs[i + 1];
            ++i;
        } else {
            return -EINVAL;
        }

        ++i;
    }

    if (name == NULL || value == NULL) {
        return -EINVAL;
    }

    mUpdate = (update != NULL) && parseBoolean(update);
    if (mUpdate != mGlobalSettings->contains(name)) {
        return -EINVAL;
    }

    mGlobalSettings->setString(name, value);
    return OK;
}

void MediaCodecList::setCurrentCodecInfo(bool encoder, const char *name, const char *type) {
    for (size_t i = 0; i < mCodecInfos.size(); ++i) {
        if (AString(name) == mCodecInfos[i]->getCodecName()) {
            if (mCodecInfos[i]->getCapabilitiesFor(type) == NULL) {
                ALOGW("Overrides with an unexpected mime %s", type);
                // Create a new MediaCodecInfo (but don't add it to mCodecInfos) to hold the
                // overrides we don't want.
                mCurrentInfo = new MediaCodecInfo(name, encoder, type);
            } else {
                mCurrentInfo = mCodecInfos.editItemAt(i);
                mCurrentInfo->updateMime(type);  // to set the current cap
            }
            return;
        }
    }
    mCurrentInfo = new MediaCodecInfo(name, encoder, type);
    // The next step involves trying to load the codec, which may
    // fail.  Only list the codec if this succeeds.
    // However, keep mCurrentInfo object around until parsing
    // of full codec info is completed.
    if (initializeCapabilities(type) == OK) {
        mCodecInfos.push_back(mCurrentInfo);
    }
}

status_t MediaCodecList::addMediaCodecFromAttributes(
        bool encoder, const char **attrs) {
    const char *name = NULL;
    const char *type = NULL;
    const char *update = NULL;

    size_t i = 0;
    while (attrs[i] != NULL) {
        if (!strcmp(attrs[i], "name")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            name = attrs[i + 1];
            ++i;
        } else if (!strcmp(attrs[i], "type")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            type = attrs[i + 1];
            ++i;
        } else if (!strcmp(attrs[i], "update")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            update = attrs[i + 1];
            ++i;
        } else {
            return -EINVAL;
        }

        ++i;
    }

    if (name == NULL) {
        return -EINVAL;
    }

    mUpdate = (update != NULL) && parseBoolean(update);
    ssize_t index = -1;
    for (size_t i = 0; i < mCodecInfos.size(); ++i) {
        if (AString(name) == mCodecInfos[i]->getCodecName()) {
            index = i;
        }
    }
    if (mUpdate != (index >= 0)) {
        return -EINVAL;
    }

    if (index >= 0) {
        // existing codec
        mCurrentInfo = mCodecInfos.editItemAt(index);
        if (type != NULL) {
            // existing type
            if (mCodecInfos[index]->getCapabilitiesFor(type) == NULL) {
                return -EINVAL;
            }
            mCurrentInfo->updateMime(type);
        }
    } else {
        // new codec
        mCurrentInfo = new MediaCodecInfo(name, encoder, type);
        // The next step involves trying to load the codec, which may
        // fail.  Only list the codec if this succeeds.
        // However, keep mCurrentInfo object around until parsing
        // of full codec info is completed.
        if (initializeCapabilities(type) == OK) {
            mCodecInfos.push_back(mCurrentInfo);
        }
    }

    return OK;
}

status_t MediaCodecList::initializeCapabilities(const char *type) {
    if (type == NULL) {
        return OK;
    }

    ALOGV("initializeCapabilities %s:%s",
            mCurrentInfo->mName.c_str(), type);

    CodecCapabilities caps;
    status_t err = QueryCodec(
            mOMX,
            mCurrentInfo->mName.c_str(),
            type,
            mCurrentInfo->mIsEncoder,
            &caps);
    if (err != OK) {
        return err;
    }

    return mCurrentInfo->initializeCapabilities(caps);
}

status_t MediaCodecList::addQuirk(const char **attrs) {
    const char *name = NULL;

    size_t i = 0;
    while (attrs[i] != NULL) {
        if (!strcmp(attrs[i], "name")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            name = attrs[i + 1];
            ++i;
        } else {
            return -EINVAL;
        }

        ++i;
    }

    if (name == NULL) {
        return -EINVAL;
    }

    mCurrentInfo->addQuirk(name);
    return OK;
}

status_t MediaCodecList::addTypeFromAttributes(const char **attrs) {
    const char *name = NULL;
    const char *update = NULL;

    size_t i = 0;
    while (attrs[i] != NULL) {
        if (!strcmp(attrs[i], "name")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            name = attrs[i + 1];
            ++i;
        } else if (!strcmp(attrs[i], "update")) {
            if (attrs[i + 1] == NULL) {
                return -EINVAL;
            }
            update = attrs[i + 1];
            ++i;
        } else {
            return -EINVAL;
        }

        ++i;
    }

    if (name == NULL) {
        return -EINVAL;
    }

    bool isExistingType = (mCurrentInfo->getCapabilitiesFor(name) != NULL);
    if (mUpdate != isExistingType) {
        return -EINVAL;
    }

    status_t ret;
    if (mUpdate) {
        ret = mCurrentInfo->updateMime(name);
    } else {
        ret = mCurrentInfo->addMime(name);
    }

    if (ret != OK) {
        return ret;
    }

    // The next step involves trying to load the codec, which may
    // fail.  Handle this gracefully (by not reporting such mime).
    if (!mUpdate && initializeCapabilities(name) != OK) {
        mCurrentInfo->removeMime(name);
    }
    return OK;
}

// legacy method for non-advanced codecs
ssize_t MediaCodecList::findCodecByType(
        const char *type, bool encoder, size_t startIndex) const {
    static const char *advancedFeatures[] = {
        "feature-secure-playback",
        "feature-tunneled-playback",
    };

    size_t numCodecs = mCodecInfos.size();
    for (; startIndex < numCodecs; ++startIndex) {
        const MediaCodecInfo &info = *mCodecInfos.itemAt(startIndex).get();

        if (info.isEncoder() != encoder) {
            continue;
        }
        sp<MediaCodecInfo::Capabilities> capabilities = info.getCapabilitiesFor(type);
        if (capabilities == NULL) {
            continue;
        }
        const sp<AMessage> &details = capabilities->getDetails();

        int32_t required;
        bool isAdvanced = false;
        for (size_t ix = 0; ix < ARRAY_SIZE(advancedFeatures); ix++) {
            if (details->findInt32(advancedFeatures[ix], &required) &&
                    required != 0) {
                isAdvanced = true;
                break;
            }
        }

        if (!isAdvanced) {
            return startIndex;
        }
    }

    return -ENOENT;
}

static status_t limitFoundMissingAttr(AString name, const char *attr, bool found = true) {
    ALOGE("limit '%s' with %s'%s' attribute", name.c_str(),
            (found ? "" : "no "), attr);
    return -EINVAL;
}

static status_t limitError(AString name, const char *msg) {
    ALOGE("limit '%s' %s", name.c_str(), msg);
    return -EINVAL;
}

static status_t limitInvalidAttr(AString name, const char *attr, AString value) {
    ALOGE("limit '%s' with invalid '%s' attribute (%s)", name.c_str(),
            attr, value.c_str());
    return -EINVAL;
}

status_t MediaCodecList::addLimit(const char **attrs) {
    sp<AMessage> msg = new AMessage();

    size_t i = 0;
    while (attrs[i] != NULL) {
        if (attrs[i + 1] == NULL) {
            return -EINVAL;
        }

        // attributes with values
        if (!strcmp(attrs[i], "name")
                || !strcmp(attrs[i], "default")
                || !strcmp(attrs[i], "in")
                || !strcmp(attrs[i], "max")
                || !strcmp(attrs[i], "min")
                || !strcmp(attrs[i], "range")
                || !strcmp(attrs[i], "ranges")
                || !strcmp(attrs[i], "scale")
                || !strcmp(attrs[i], "value")) {
            msg->setString(attrs[i], attrs[i + 1]);
            ++i;
        } else {
            return -EINVAL;
        }
        ++i;
    }

    AString name;
    if (!msg->findString("name", &name)) {
        ALOGE("limit with no 'name' attribute");
        return -EINVAL;
    }

    // size, blocks, bitrate, frame-rate, blocks-per-second, aspect-ratio: range
    // quality: range + default + [scale]
    // complexity: range + default
    bool found;

    if (name == "aspect-ratio" || name == "bitrate" || name == "block-count"
            || name == "blocks-per-second" || name == "complexity"
            || name == "frame-rate" || name == "quality" || name == "size") {
        AString min, max;
        if (msg->findString("min", &min) && msg->findString("max", &max)) {
            min.append("-");
            min.append(max);
            if (msg->contains("range") || msg->contains("value")) {
                return limitError(name, "has 'min' and 'max' as well as 'range' or "
                        "'value' attributes");
            }
            msg->setString("range", min);
        } else if (msg->contains("min") || msg->contains("max")) {
            return limitError(name, "has only 'min' or 'max' attribute");
        } else if (msg->findString("value", &max)) {
            min = max;
            min.append("-");
            min.append(max);
            if (msg->contains("range")) {
                return limitError(name, "has both 'range' and 'value' attributes");
            }
            msg->setString("range", min);
        }

        AString range, scale = "linear", def, in_;
        if (!msg->findString("range", &range)) {
            return limitError(name, "with no 'range', 'value' or 'min'/'max' attributes");
        }

        if ((name == "quality" || name == "complexity") ^
                (found = msg->findString("default", &def))) {
            return limitFoundMissingAttr(name, "default", found);
        }
        if (name != "quality" && msg->findString("scale", &scale)) {
            return limitFoundMissingAttr(name, "scale");
        }
        if ((name == "aspect-ratio") ^ (found = msg->findString("in", &in_))) {
            return limitFoundMissingAttr(name, "in", found);
        }

        if (name == "aspect-ratio") {
            if (!(in_ == "pixels") && !(in_ == "blocks")) {
                return limitInvalidAttr(name, "in", in_);
            }
            in_.erase(5, 1); // (pixel|block)-aspect-ratio
            in_.append("-");
            in_.append(name);
            name = in_;
        }
        if (name == "quality") {
            mCurrentInfo->addDetail("quality-scale", scale);
        }
        if (name == "quality" || name == "complexity") {
            AString tag = name;
            tag.append("-default");
            mCurrentInfo->addDetail(tag, def);
        }
        AString tag = name;
        tag.append("-range");
        mCurrentInfo->addDetail(tag, range);
    } else {
        AString max, value, ranges;
        if (msg->contains("default")) {
            return limitFoundMissingAttr(name, "default");
        } else if (msg->contains("in")) {
            return limitFoundMissingAttr(name, "in");
        } else if ((name == "channel-count") ^
                (found = msg->findString("max", &max))) {
            return limitFoundMissingAttr(name, "max", found);
        } else if (msg->contains("min")) {
            return limitFoundMissingAttr(name, "min");
        } else if (msg->contains("range")) {
            return limitFoundMissingAttr(name, "range");
        } else if ((name == "sample-rate") ^
                (found = msg->findString("ranges", &ranges))) {
            return limitFoundMissingAttr(name, "ranges", found);
        } else if (msg->contains("scale")) {
            return limitFoundMissingAttr(name, "scale");
        } else if ((name == "alignment" || name == "block-size"
                || name == "max-supported-instances") ^
                (found = msg->findString("value", &value))) {
            return limitFoundMissingAttr(name, "value", found);
        }

        if (max.size()) {
            AString tag = "max-";
            tag.append(name);
            mCurrentInfo->addDetail(tag, max);
        } else if (value.size()) {
            mCurrentInfo->addDetail(name, value);
        } else if (ranges.size()) {
            AString tag = name;
            tag.append("-ranges");
            mCurrentInfo->addDetail(tag, ranges);
        } else {
            ALOGW("Ignoring unrecognized limit '%s'", name.c_str());
        }
    }
    return OK;
}

status_t MediaCodecList::addFeature(const char **attrs) {
    size_t i = 0;
    const char *name = NULL;
    int32_t optional = -1;
    int32_t required = -1;
    const char *value = NULL;

    while (attrs[i] != NULL) {
        if (attrs[i + 1] == NULL) {
            return -EINVAL;
        }

        // attributes with values
        if (!strcmp(attrs[i], "name")) {
            name = attrs[i + 1];
            ++i;
        } else if (!strcmp(attrs[i], "optional") || !strcmp(attrs[i], "required")) {
            int value = (int)parseBoolean(attrs[i + 1]);
            if (!strcmp(attrs[i], "optional")) {
                optional = value;
            } else {
                required = value;
            }
            ++i;
        } else if (!strcmp(attrs[i], "value")) {
            value = attrs[i + 1];
            ++i;
        } else {
            return -EINVAL;
        }
        ++i;
    }
    if (name == NULL) {
        ALOGE("feature with no 'name' attribute");
        return -EINVAL;
    }

    if (optional == required && optional != -1) {
        ALOGE("feature '%s' is both/neither optional and required", name);
        return -EINVAL;
    }

    if ((optional != -1 || required != -1) && (value != NULL)) {
        ALOGE("feature '%s' has both a value and optional/required attribute", name);
        return -EINVAL;
    }

    if (value != NULL) {
        mCurrentInfo->addFeature(name, value);
    } else {
        mCurrentInfo->addFeature(name, (required == 1) || (optional == 0));
    }
    return OK;
}

ssize_t MediaCodecList::findCodecByName(const char *name) const {
    for (size_t i = 0; i < mCodecInfos.size(); ++i) {
        const MediaCodecInfo &info = *mCodecInfos.itemAt(i).get();

        if (info.mName == name) {
            return i;
        }
    }

    return -ENOENT;
}

size_t MediaCodecList::countCodecs() const {
    return mCodecInfos.size();
}

const sp<AMessage> MediaCodecList::getGlobalSettings() const {
    return mGlobalSettings;
}

}  // namespace android