ffmpeg: libjniaudio on gingerbread

最新推荐文章于 2022-03-03 22:30:00 发布

最新推荐文章于 2022-03-03 22:30:00 发布 · 69 阅读

文章标签：

#ffmpeg #移动开发

本文详细介绍了如何解决在Galaxy S设备上使用FFmpeg时遇到的音频库libjniaudio和视频库libjnivideo相关的问题。包括通过调整代码以兼容不同Android版本的音频跟踪和视频表面类的变化。

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Hi,

I tried to run the ffpmeg app on Galaxy S with v. 2.3.3. Issue#1was withlibjniaudio- due to change of signature of android::AudioTrack::set().

Follows my patch for audiotrack.cpp, functionAndroidAudioTrack_set():

status_t ret = NAME_NOT_FOUND;

void *lptr_media = dlopen("libmedia.so", 0);
__android_log_print(ANDROID_LOG_DEBUG, TAG, "dlopen returns %p", lptr_media);

if (lptr_media)         // first, try gingerbread
{
    status_t (*fptr_set)(AudioTrack* track,
                        int streamType,
                        uint32_t sampleRate,
                        int format,
                        int channels,
                        int frameCount,
                        uint32_t flags,
                        AudioTrack::callback_t cbf,
                        void* user,
                        int notificationFrames,
                        const sp<IMemory>& sharedBuffer,
                        bool threadCanCallJava,
                        int sessionId);

    fptr_set = (typeof fptr_set)dlsym(lptr_media, "_ZN7android10AudioTrack3setEijiiijPFviPvS1_ES1_iRKNS_2spINS_7IMemoryEEEbi");
    __android_log_print(ANDROID_LOG_DEBUG, TAG, "dlsym returns %p", fptr_set);

    if (fptr_set != 0)
    {
        ret = fptr_set(track,
                       streamType,
                       sampleRate,
                       format,
                       channels,
                       0, 0, 0, 0, 0, 0, 0, 0);
        __android_log_print(ANDROID_LOG_DEBUG, TAG, "fptr_set() returns %d", ret);
        dlclose(lptr_media);
        lptr_media = 0;
    }
}

if (lptr_media)         // second, try froyo
{
    status_t (*fptr_set)(AudioTrack* track,
                        int streamType,
                        uint32_t sampleRate,
                        int format,
                        int channels,
                        int frameCount,
                        uint32_t flags,
                        AudioTrack::callback_t cbf,
                        void* user,
                        int notificationFrames,
                        const sp<IMemory>& sharedBuffer,
                        bool threadCanCallJava);

    fptr_set = (typeof fptr_set)dlsym(lptr_media, "_ZN7android10AudioTrack3setEijiiijPFviPvS1_ES1_iRKNS_2spINS_7IMemoryEEEb");
    __android_log_print(ANDROID_LOG_INFO, TAG, "dlsym returns %p", fptr_set);

    if (fptr_set != 0)
    {
        ret = fptr_set(track,
                       streamType,
                       sampleRate,
                       format,
                       channels,
                       0, 0, 0, 0, 0, 0, 0); // push max number of parameters
        __android_log_print(ANDROID_LOG_INFO, TAG, "fptr_set() returns %d", ret);
        dlclose(lptr_media);
        lptr_media = 0;
    }
}

if (lptr_media)         // finally, close library anyway
{
    dlclose(lptr_media);
}

ffmpeg: libjnivideo on gingerbread

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No one is assigned

Hi,

I tried to run the ffpmeg app on Galaxy S with v. 2.3.3. Issue#2was withlibjnivideo- due to change of name of the native surface field inandroid/view/Surfaceclass.

Follows my patch forsurface.cpp, functiongetNativeSurface():

static Surface* getNativeSurface(JNIEnv* env, jobject jsurface) { jclass clazz = env->FindClass("android/view/Surface"); jfieldID field_surface = env->GetFieldID(clazz, "mSurface", "I"); if(field_surface == NULL) { #ifdef ANDROID_VIEW_SURFACE_JNI_ID // using gingerbread version of <surfaceflinger/Surface.h> env->ExceptionClear(); field_surface = env->GetFieldID(clazz, ANDROID_VIEW_SURFACE_JNI_ID, "I"); #endif } if(field_surface == NULL) { return NULL; } return (Surface *) env->GetIntField(jsurface, field_surface); }

alexcohn, havlenapetr, and sunruiare participating in this issue.

sunruicommented

about 7 hours ago

hi, you should change the mSurface to mNativeSurface with under above 2.3.
BTW, how to compile with neon or vfp?

havlenapetrcommented

about an hour ago

yes I know, better way will be add ifdef for OS version, neon or vfp support zou must set in config.h of ffmpeg, but I think that better way is compile ffmpeg with theirs makefiles and than use this libffmpeg.so like prebuilt library in android's project

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