VuoAvPlayerObject.m

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#import "VuoAvPlayerObject.h"
#include "VuoCompositionState.h"
#include "VuoImageRenderer.h"
#include <OpenGL/OpenGL.h>
#include <OpenGL/CGLMacro.h>
#include "module.h"
#include "VuoGlPool.h"
#include "VuoVideoFrame.h"
#include <QuartzCore/CoreImage.h>
#include <Quartz/Quartz.h>
#include <QuartzCore/CVImageBuffer.h>
#include "VuoAvPlayerInterface.h"
#include <Accelerate/Accelerate.h>
#include "VuoWindow.h"
#include "VuoOsStatus.h"
#include "VuoApp.h"
#include "HapInAVFoundation.h"
 
#ifdef VUO_COMPILER
VuoModuleMetadata({
                     "title" : "VuoAvPlayerObject",
                     "dependencies" : [
                        "VuoImage",
                        "VuoWindow",
                        "AVFoundation.framework",
                        "VuoImageRenderer",
                        "CoreVideo.framework",
                        "CoreMedia.framework",
                        "VuoGlContext",
                        "Accelerate.framework",
                        "VuoOsStatus",
 
                        // @todo
                        "QuartzCore.framework",
                        "Quartz.framework"
 
                     ]
                 });
#endif
 
const unsigned int AUDIO_BUFFER_SIZE = 16384;
 
const unsigned int REVERSE_PLAYBACK_FRAME_ADVANCE = 10;
 
 
@protocol VuoAvTrackHapFrame
@property (readonly) OSType codecSubType;
@property (readonly) int dxtPlaneCount;
@property (readonly) void** dxtDatas;
@property (readonly) OSType* dxtPixelFormats;
@property (readonly) NSSize dxtImgSize;
@property (readonly) CMTime presentationTime;
@end
 
@protocol VuoAvTrackHapOutput
- (id)initWithHapAssetTrack:(AVAssetTrack *)track;
- (NSObject<VuoAvTrackHapFrame> *) allocFrameForHapSampleBuffer:(CMSampleBufferRef)n;
@end
 
@interface VuoAvTrackOutput : AVAssetReaderTrackOutput
{
    NSObject<VuoAvTrackHapOutput> *hapOutput;   
}
@end
 
@implementation VuoAvTrackOutput
 
- (id)initWithTrack:(AVAssetTrack *)track outputSettings:(NSDictionary *)settings
{
    bool isHap = false;
    for (id formatDescription in track.formatDescriptions)
    {
        CMFormatDescriptionRef desc = (CMFormatDescriptionRef) formatDescription;
        CMVideoCodecType codec = CMFormatDescriptionGetMediaSubType(desc);
        if (codec == 'Hap1'
         || codec == 'Hap5'
         || codec == 'HapY'
         || codec == 'HapM')
        {
            isHap = true;
            break;
        }
    }
 
    if (self = [super initWithTrack:track outputSettings:(isHap ? nil : settings)])
    {
        if (isHap)
        {
            NSBundle *f = [NSBundle bundleWithPath:[NSString stringWithFormat:@"%s/Vuo.framework/Versions/%s/Frameworks/HapInAVFoundation.framework",
                                                                              VuoGetFrameworkPath(),
                                                                              VUO_FRAMEWORK_VERSION_STRING]];
            if (!f)
            {
                f = [NSBundle bundleWithPath:[NSString stringWithFormat:@"%s/VuoRunner.framework/Versions/%s/Frameworks/HapInAVFoundation.framework",
                                                                        VuoGetRunnerFrameworkPath(),
                                                                        VUO_FRAMEWORK_VERSION_STRING]];
                if (!f)
                {
                    VUserLog("Error: Playing this movie requires HapInAVFoundation.framework, but I can't find it.");
                    return nil;
                }
            }
 
            if (![f isLoaded])
            {
                NSError *error;
                bool status = [f loadAndReturnError:&error];
                if (!status)
                {
                    NSError *underlyingError = [[error userInfo] objectForKey:NSUnderlyingErrorKey];
                    if (underlyingError)
                        error = underlyingError;
                    VUserLog("Error: Playing this movie requires HapInAVFoundation.framework, but it wouldn't load: %s", [[error localizedDescription] UTF8String]);
                    return nil;
                }
            }
 
            hapOutput = [[NSClassFromString(@"AVPlayerItemHapDXTOutput") alloc] initWithHapAssetTrack:track];
        }
    }
    return self;
}
 
- (NSObject<VuoAvTrackHapFrame> *)newHapFrame
{
    if (!hapOutput)
        return nil;
 
    CMSampleBufferRef buffer = [super copyNextSampleBuffer];
    if (!buffer)
        return nil;
    VuoDefer(^{ CFRelease(buffer); });
 
    return [hapOutput allocFrameForHapSampleBuffer:buffer];
}
 
- (void)dealloc
{
    [hapOutput release];
    [super dealloc];
}
 
@end
 
 
@implementation VuoAvPlayerObject
 
- (id) init
{
    // It seems we need an NSApplication instance to exist prior to using AVFoundation; otherwise, the app beachballs.
    // https://b33p.net/kosada/node/11006
    VuoApp_init(false);
 
    self = [super init];
 
    if (self)
    {
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        CGLPixelFormatObj pf = VuoGlContext_makePlatformPixelFormat(false, false, -1);
        __block CVReturn ret;
        VuoGlContext_perform(^(CGLContextObj cgl_ctx){
            ret = CVOpenGLTextureCacheCreate(NULL, NULL, cgl_ctx, pf, NULL, &textureCache);
        });
        CGLReleasePixelFormat(pf);
#pragma clang diagnostic pop
        if (ret != kCVReturnSuccess)
        {
            VUserLog("Error: Couldn't create texture cache: %d", ret);
            return nil;
        }
 
        isReady = false;
        playOnReady = false;
        videoTimestamp = 0;
        audioTimestamp = 0;
        assetReader = nil;
        containsUnplayableAudio = false;
 
        readyToPlayCallback = NULL;
        avDecoderCppObject = NULL;
 
        videoQueue = [[NSMutableArray alloc] init];
 
        audioBufferCapacity = sizeof(Float32) * AUDIO_BUFFER_SIZE;
        audioBuffer = (Float32*) malloc(audioBufferCapacity);
    }
 
    return self;
}
 
+ (void) releaseAssetReader:(AVAssetReader*)reader
{
    AVAssetReader* readerToRelease = reader;
 
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, .2 * NSEC_PER_SEC), dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^
    {
        if (readerToRelease.status == AVAssetReaderStatusReading)
            [readerToRelease cancelReading];
 
        [readerToRelease release];
    });
}
 
- (void) dealloc
{
    if(assetReader != nil)
        [VuoAvPlayerObject releaseAssetReader:assetReader];
 
    if(asset != nil)
    {
        [asset cancelLoading];
        [asset release];
    }
 
    readyToPlayCallback = NULL;
    avDecoderCppObject = NULL;
 
    VuoGlContext_perform(^(CGLContextObj cgl_ctx){
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        CVOpenGLTextureCacheRelease(textureCache);
#pragma clang diagnostic pop
    });
 
    [self clearFrameQueue];
 
    [videoQueue release];
 
    if(audioBuffer != nil)
        free(audioBuffer);
 
    [super dealloc];
}
 
- (bool) setURL:(NSURL*)url
{
    asset = [AVAsset assetWithURL:url];
 
    if(asset == nil)
    {
        VUserLog("VuoVideoDecoder: AvFoundation decoder could not find movie file at path: %s", [[url absoluteString] UTF8String]);
        return false;
    }
 
    [asset retain];
 
    // Movies using the Hap codec are not "playable" yet we can still play them.
    // Also, https://developer.apple.com/videos/play/wwdc2017/511?time=293 says `isPlayable`
    // means that the current hardware is capable of playing back the current media in realtime,
    // but we can ignore that since we want to try to play regardless.
    bool isPlayable = true; //[asset isPlayable];
 
    // "Currently, only Apple can 'make' protected content and applications that can play it."
    // http://www.cocoabuilder.com/archive/cocoa/301980-avfoundation-authorization-for-playback-of-protected-content.html#301981
    bool isProtected = [asset hasProtectedContent];
 
    if (!isPlayable || isProtected || ![asset isReadable])
    {
        VUserLog("AvFoundation cannot play this asset (isPlayable=%d, hasProtectedContent=%d, isReadable=%d).",
                 [asset isPlayable], [asset hasProtectedContent], [asset isReadable]);
        isReady = false;
        return false;
    }
 
 
    NSArray *videoTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
    if (videoTracks.count)
    {
        AVAssetTrack *videoTrack = videoTracks[0];
        CMFormatDescriptionRef desc = (CMFormatDescriptionRef)videoTrack.formatDescriptions[0];
        CMVideoCodecType codec = CMFormatDescriptionGetMediaSubType(desc);
        if (codec == 'ap4h'  // AVVideoCodecTypeAppleProRes4444
         || codec == 'Hap5'  // Hap Alpha
         || codec == 'HapM'  // Hap Q Alpha
         || codec == 'HapA') // Hap Alpha-only
            hasAlpha = true;
        if (codec == 'hvc1') // HEVC movies may have an alpha attachment.
        {
            CFBooleanRef containsAlphaChannel = CMFormatDescriptionGetExtension(desc, CFSTR("ContainsAlphaChannel"));  // kCMFormatDescriptionExtension_ContainsAlphaChannel (macOS 10.15+)
            if (containsAlphaChannel == kCFBooleanTrue)
                hasAlpha = true;
        }
 
        if (VuoIsDebugEnabled())
        {
            char *codecZ = VuoOsStatus_getText(codec);
            int bitsPerComponent = ((NSNumber *)CMFormatDescriptionGetExtension(desc, CFSTR("BitsPerComponent"))).intValue;
            int depth            = ((NSNumber *)CMFormatDescriptionGetExtension(desc, CFSTR("Depth"))).intValue;
 
            VuoText codecName = VuoText_makeFromCFString(CMFormatDescriptionGetExtension(desc, CFSTR("FormatName")));
            VuoRetain(codecName);
            VuoText alphaMode = VuoText_makeFromCFString(CMFormatDescriptionGetExtension(desc, CFSTR("AlphaChannelMode")));
            VuoRetain(alphaMode);
            VUserLog("codec=\"%s\" (%s)  bpc=%d  depth=%d  hasAlpha=%d %s",
                     codecName,
                     codecZ,
                     bitsPerComponent,
                     depth,
                     hasAlpha,
                     (hasAlpha && alphaMode) ? alphaMode : "");
            VuoRelease(codecName);
            VuoRelease(alphaMode);
            free(codecZ);
        }
    }
 
 
    NSArray* assetKeys = @[@"playable", @"hasProtectedContent", @"tracks"];
 
    void *compositionState = vuoCopyCompositionStateFromThreadLocalStorage();
    
 
 
[asset loadValuesAsynchronouslyForKeys: assetKeys completionHandler:^(void)
    {
        vuoAddCompositionStateToThreadLocalStorage(compositionState);
 
        // First test whether the values of each of the keys we need have been successfully loaded.
        NSError *error = nil;
        bool failedLoading = false;
 
        for (NSString *key in assetKeys)
        {
            NSInteger status = [asset statusOfValueForKey:key error:&error];
 
            if( error != nil ||
                status == AVKeyValueStatusFailed ||
                status == AVKeyValueStatusCancelled )
            {
                VUserLog("AVFoundation failed loading asset.");
                failedLoading = true;
                break;
            }
        }
        isReady = !failedLoading && [self setAssetReaderTimeRange:CMTimeRangeMake(kCMTimeZero, [asset duration])];
 
        if(isReady)
        {
            for(int i = 0; i < 3; i++)
            {
                 if(![self copyNextVideoSampleBuffer])
                 {
                    VUserLog("AvFoundation successfully loaded but failed to extract a video buffer.");
                    isReady = false;
                    break;
                 }
            }
        }
        // dispatch_async(dispatch_get_main_queue(), ^{
            if( self != nil && readyToPlayCallback != NULL && avDecoderCppObject != NULL )
                readyToPlayCallback( avDecoderCppObject, isReady );
        // });
 
        vuoRemoveCompositionStateFromThreadLocalStorage();
    }];
 
    return true;
}
 
- (bool) canBeginPlayback
{
    return isReady;
}
 
- (bool) canPlayAudio
{
    return !containsUnplayableAudio;
}
 
- (double) getFrameRate
{
    return nominalFrameRate;
}
 
- (bool) setAssetReaderTimeRange:(CMTimeRange)timeRange
{
    NSError *error = nil;
 
    if(assetReader != nil)
    {
        [VuoAvPlayerObject releaseAssetReader:assetReader];
 
        assetReaderVideoTrackOutput = nil;
        assetReaderAudioTrackOutput = nil;
    }
 
    NSArray* videoTracks = [asset tracksWithMediaType:AVMediaTypeVideo];
 
    if ([videoTracks count] != 0)
    {
        AVAssetTrack* vidtrack = [videoTracks objectAtIndex:0];
 
        // for (id formatDescription in vidtrack.formatDescriptions)
        // {
        //     CMFormatDescriptionRef desc = (CMFormatDescriptionRef) formatDescription;
        //     CMVideoCodecType codec = CMFormatDescriptionGetMediaSubType(desc);
 
        //     /// jpeg files either don't play or have terrible performance with AVAssetReader,
        //     if(codec == kCMVideoCodecType_JPEG || codec == kCMVideoCodecType_JPEG_OpenDML)
        //     {
        //      VUserLog("AVFoundation detected video codec is JPEG or MJPEG.");
        //      return false;
        //     }
        // }
 
        nominalFrameRate = [vidtrack nominalFrameRate];
 
        assetReader = [AVAssetReader assetReaderWithAsset:asset error:&error];
 
        [assetReader retain];
 
        if(error) {
            VUserLog("AVAssetReader failed initialization: %s", [[error localizedDescription] UTF8String]);
            return false;
        }
 
        assetReader.timeRange = timeRange;
 
        NSDictionary *videoOutputSettings = @{
            (NSString *)kCVPixelBufferPixelFormatTypeKey: @(kCVPixelFormatType_32BGRA),
            (NSString *)kCVPixelBufferOpenGLCompatibilityKey: @(YES),
        };
 
        assetReaderVideoTrackOutput = [VuoAvTrackOutput assetReaderTrackOutputWithTrack:vidtrack
            outputSettings:videoOutputSettings];
        if (!assetReaderVideoTrackOutput)
            return false;
 
        if([assetReader canAddOutput:assetReaderVideoTrackOutput])
        {
            [assetReader addOutput:assetReaderVideoTrackOutput];
        }
        else
        {
            VUserLog("AVFoundation Video Decoder: assetReaderVideoTrackOutput cannot be added to assetReader.");
            return false;
        }
 
 
        NSDictionary* audioOutputSettings;
 
            audioOutputSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                    [NSNumber numberWithInt: kAudioFormatLinearPCM ], AVFormatIDKey,
                                    [NSNumber numberWithFloat: VuoAudioSamples_sampleRate], AVSampleRateKey,
                                    [NSNumber numberWithInt:32], AVLinearPCMBitDepthKey,
                                    [NSNumber numberWithBool:NO], AVLinearPCMIsBigEndianKey,
                                    [NSNumber numberWithBool:YES], AVLinearPCMIsFloatKey,
                                    [NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
                                    nil];
 
        // AVAssetTrack.playable isn't available pre-10.8, so just try to create the AVAssetTrackReaderOutput out
        // of every audio track until either one sticks or we run out of tracks.
        for(AVAssetTrack* track in [asset tracksWithMediaType:AVMediaTypeAudio])
        {
            if(track == nil)
                continue;
 
            audioChannelCount = [self getAudioChannelCount:track];
 
            if(audioChannelCount < 1)
            {
                containsUnplayableAudio = true;
                continue;
            }
 
            assetReaderAudioTrackOutput = [AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:track outputSettings:audioOutputSettings];
 
            if(assetReaderAudioTrackOutput != nil && [assetReader canAddOutput:assetReaderAudioTrackOutput])
            {
                [assetReader addOutput:assetReaderAudioTrackOutput];
                containsUnplayableAudio = false;
                break;
            }
            else
            {
                VUserLog("AVFoundation Video Decoder: AssetReaderAudioTrackOutput cannot be added to assetReader.");
                audioChannelCount = 0;
                containsUnplayableAudio = true;
                continue;
            }
        }
 
        return [assetReader startReading];
    }
    else
    {
        VUserLog("No video track found!");
        return false;
    }
}
 
- (unsigned int) getAudioChannelCount:(AVAssetTrack*) track
{
    NSArray* formatDesc = track.formatDescriptions;
 
    for(unsigned int i = 0; i < [formatDesc count]; ++i)
    {
        CMAudioFormatDescriptionRef item = (CMAudioFormatDescriptionRef)[formatDesc objectAtIndex:i];
        const AudioStreamBasicDescription* audioDescription = CMAudioFormatDescriptionGetStreamBasicDescription (item);
 
        if(audioDescription != nil)
        {
            return audioDescription->mChannelsPerFrame;
        }
    }
 
    return 0;
}
 
- (void) setPlaybackRate:(double)rate
{
    if(playbackRate < 0 != rate < 0)
    {
        // if was reverse and now is forward
        if(rate > 0)
            [self seekToSecond:videoTimestamp withRange:-1 frame:NULL];
        else
            [self clearFrameQueue];
    }
 
    playbackRate = rate;
}
 
- (bool) audioEnabled
{
    return VuoReal_areEqual(playbackRate, 1);
}
 
- (unsigned int) audioChannels
{
    return audioChannelCount;
}
 
- (void) clearFrameQueue
{
    for(int i = 0; i < [videoQueue count]; i++)
    {
        VuoVideoFrame* frame = [[videoQueue objectAtIndex:i] pointerValue];
        VuoVideoFrame_release(*frame);
        free(frame);
    }
 
    [videoQueue removeAllObjects];
 
    audioBufferSampleIndex = 0;
    audioBufferSamplesPerChannel = 0;
}
 
- (bool) seekToSecond:(float)second withRange:(float)range frame:(VuoVideoFrame *)frame
{
    if(![self canBeginPlayback])
        return false;
 
    [self clearFrameQueue];
 
    if (playbackRate < 0 && VuoReal_areEqual(second, CMTimeGetSeconds(asset.duration)))
    {
        float preroll = (1./nominalFrameRate * REVERSE_PLAYBACK_FRAME_ADVANCE);
        second -= preroll;
    }
 
    CMTime cmsec = CMTimeMakeWithSeconds(second, NSEC_PER_SEC);
 
    [self setAssetReaderTimeRange: CMTimeRangeMake(cmsec, range < 0 ? [asset duration] : CMTimeMakeWithSeconds(range, NSEC_PER_SEC))];
 
    // read one sample to get an accurate timestamp
    [self copyNextVideoSampleBuffer];
    [self copyNextAudioSampleBuffer];
 
    if([videoQueue count] > 0)
    {
        videoTimestamp = ((VuoVideoFrame*)[[videoQueue objectAtIndex:0] pointerValue])->timestamp;
    }
    else if(second >= [self getDuration])
    {
        videoTimestamp = [self getDuration];
    }
 
    if (frame)
        if (![self nextVideoFrame:frame])
        {
            frame->image = NULL;
            frame->timestamp = 0;
            frame->duration = 0;
        }
 
    return true;
}
 
- (void) setPlayerCallback:(void (*)(void* functionPtr, bool canPlayMedia))callback target:(void*)decoderCppObject
{
    readyToPlayCallback = callback;
    avDecoderCppObject = decoderCppObject;
}
 
- (VuoReal) getCurrentTimestamp
{
    return (VuoReal) videoTimestamp;
}
 
- (bool) nextVideoFrame:(VuoVideoFrame*)frame
{
    if([videoQueue count] < 1)
    {
        if( playbackRate < 0)
        {
            if(![self decodePreceedingVideoSamples])
                return false;
        }
        else
        {
            if(![self copyNextVideoSampleBuffer] )
                return false;
        }
 
        if ([videoQueue count] < 1)
            return false;
    }
 
    int index = playbackRate < 0 ? [videoQueue count] - 1 : 0;
 
    NSValue* value = [videoQueue objectAtIndex:index];
    VuoVideoFrame* framePointer = [value pointerValue];
    *frame = *framePointer;
    videoTimestamp = frame->timestamp;
    [videoQueue removeObjectAtIndex:index];
 
    free(framePointer);
 
    return true;
}
 
- (bool) decodePreceedingVideoSamples
{
    float rewindIncrement = (1./nominalFrameRate * REVERSE_PLAYBACK_FRAME_ADVANCE);
 
    if(videoTimestamp <= 0.)
        return false;
 
    float seek = fmax(0, videoTimestamp - rewindIncrement);
    [self seekToSecond:seek withRange:rewindIncrement frame:NULL];
 
    while([self copyNextVideoSampleBuffer]) {}
 
    return [videoQueue count] > 0;
}
 
- (VuoReal) getDuration
{
    return (VuoReal) CMTimeGetSeconds([asset duration]);
}
 
- (bool) nextAudioFrame:(VuoAudioFrame*) frame
{
    if(![self audioEnabled])
        return false;
 
    int sampleIndex = 0;
    int sampleCapacity = VuoAudioSamples_bufferSize;
 
    for(int i = 0; i < audioChannelCount; i++)
    {
        VuoAudioSamples samples = VuoAudioSamples_alloc(VuoAudioSamples_bufferSize);
        samples.samplesPerSecond = VuoAudioSamples_sampleRate;
        VuoListAppendValue_VuoAudioSamples(frame->channels, samples);
    }
 
    while(sampleIndex < sampleCapacity - 1)
    {
        if(audioBufferSampleIndex >= audioBufferSamplesPerChannel)
        {
            if(![self copyNextAudioSampleBuffer])
            {
                return false;
            }
        }
 
        unsigned int copyLength = MIN(sampleCapacity - sampleIndex, audioBufferSamplesPerChannel - audioBufferSampleIndex);
 
        for(int i = 0; i < audioChannelCount; i++)
        {
            VuoReal* frame_samples = VuoListGetValue_VuoAudioSamples(frame->channels, i+1).samples;
            int frame_sample_index = sampleIndex, buffer_sample_index = audioBufferSampleIndex;
 
            for(int iterator = 0; iterator < copyLength; iterator++)
            {
                frame_samples[frame_sample_index] = audioBuffer[buffer_sample_index * audioChannelCount + i];
 
                frame_sample_index++;
                buffer_sample_index++;
            }
        }
 
        sampleIndex += copyLength;
        audioBufferSampleIndex += copyLength;
    }
 
    frame->timestamp = audioTimestamp;
 
    return true;
}
 
static void VuoAvPlayerObject_freeCallback(VuoImage imageToFree)
{
}
 
- (bool) copyNextVideoSampleBuffer
{
    if( [assetReader status] == AVAssetReaderStatusReading )
    {
        __block VuoImage image = NULL;
        float timestamp;
        float duration;
        NSObject<VuoAvTrackHapFrame> *hapFrame = [assetReaderVideoTrackOutput newHapFrame];
        if (hapFrame)
        {
            // For Hap frames, get the DXT buffer in CPU memory, and upload it to the GPU.
 
            timestamp = CMTimeGetSeconds(hapFrame.presentationTime);
            duration = 1./nominalFrameRate;
            int dxtPlaneCount = hapFrame.dxtPlaneCount;
            OSType *dxtPixelFormats = hapFrame.dxtPixelFormats;
            void **dxtBaseAddresses = hapFrame.dxtDatas;
 
            if (dxtPlaneCount > 2)
            {
                VUserLog("Error: This image has %d planes, which isn't part of the Hap spec.", dxtPlaneCount);
                return false;
            }
 
            VuoGlContext_perform(^(CGLContextObj cgl_ctx){
                VuoImage dxtImage[dxtPlaneCount];
                for (int i = 0; i < dxtPlaneCount; ++i)
                {
                    GLuint internalFormat;
                    unsigned int bitsPerPixel;
                    switch (dxtPixelFormats[i])
                    {
                        case kHapCVPixelFormat_RGB_DXT1:
                            internalFormat = HapTextureFormat_RGB_DXT1;
                            bitsPerPixel = 4;
                            break;
 
                        case kHapCVPixelFormat_RGBA_DXT5:
                        case kHapCVPixelFormat_YCoCg_DXT5:
                            internalFormat = HapTextureFormat_RGBA_DXT5;
                            bitsPerPixel = 8;
                            break;
 
                        case kHapCVPixelFormat_CoCgXY:
                            if (i == 0)
                            {
                                internalFormat = HapTextureFormat_RGBA_DXT5;
                                bitsPerPixel = 8;
                            }
                            else
                            {
                                internalFormat = HapTextureFormat_A_RGTC1;
                                bitsPerPixel = 4;
                            }
                            break;
 
                        case kHapCVPixelFormat_YCoCg_DXT5_A_RGTC1:
                            if (i == 0)
                            {
                                internalFormat = HapTextureFormat_RGBA_DXT5;
                                bitsPerPixel = 8;
                            }
                            else
                            {
                                internalFormat = HapTextureFormat_A_RGTC1;
                                bitsPerPixel = 4;
                            }
                            break;
 
                        case kHapCVPixelFormat_A_RGTC1:
                            internalFormat = HapTextureFormat_A_RGTC1;
                            bitsPerPixel = 4;
                            break;
 
                        default:
                            VUserLog("Error: Unknown Hap dxtPixelFormat %s.", VuoOsStatus_getText(dxtPixelFormats[i]));
                            return;
                    }
 
                    GLuint texture = VuoGlTexturePool_use(cgl_ctx, VuoGlTexturePool_NoAllocation, GL_TEXTURE_2D, internalFormat, hapFrame.dxtImgSize.width, hapFrame.dxtImgSize.height, GL_RGBA, NULL);
                    glBindTexture(GL_TEXTURE_2D, texture);
 
                    size_t bytesPerRow = (hapFrame.dxtImgSize.width * bitsPerPixel) / 8;
                    GLsizei dataLength = (int)(bytesPerRow * hapFrame.dxtImgSize.height);
 
                    glPixelStorei(GL_UNPACK_CLIENT_STORAGE_APPLE, GL_TRUE);
 
                    glCompressedTexImage2D(GL_TEXTURE_2D, 0, internalFormat, hapFrame.dxtImgSize.width, hapFrame.dxtImgSize.height, 0, dataLength, dxtBaseAddresses[i]);
 
                    glPixelStorei(GL_UNPACK_CLIENT_STORAGE_APPLE, GL_FALSE);
                    glBindTexture(GL_TEXTURE_2D, 0);
 
                    dxtImage[i] = VuoImage_make(texture, internalFormat, hapFrame.dxtImgSize.width, hapFrame.dxtImgSize.height);
                }
 
                if (hapFrame.codecSubType == kHapCodecSubType
                 || hapFrame.codecSubType == kHapAlphaCodecSubType)
                    image = VuoImage_makeCopy(dxtImage[0], true, 0, 0, false);
                else if (hapFrame.codecSubType == kHapYCoCgCodecSubType)
                {
                    // Based on https://github.com/Vidvox/hap-in-avfoundation/blob/master/HapInAVF%20Test%20App/ScaledCoCgYToRGBA.frag
                    static const char *fragmentShader = VUOSHADER_GLSL_SOURCE(120,
                        uniform sampler2D cocgsy_src;
                        const vec4 offsets = vec4(-0.50196078431373, -0.50196078431373, 0.0, 0.0);
                        varying vec2 fragmentTextureCoordinate;
                        void main()
                        {
                            vec4 CoCgSY = texture2D(cocgsy_src, vec2(fragmentTextureCoordinate.x, 1. - fragmentTextureCoordinate.y));
 
                            CoCgSY += offsets;
 
                            float scale = ( CoCgSY.z * ( 255.0 / 8.0 ) ) + 1.0;
 
                            float Co = CoCgSY.x / scale;
                            float Cg = CoCgSY.y / scale;
                            float Y = CoCgSY.w;
 
                            gl_FragColor = vec4(Y + Co - Cg, Y + Cg, Y - Co - Cg, 1.0);
                        }
                    );
 
                    VuoShader shader = VuoShader_make("YCoCg to RGB Shader");
                    VuoRetain(shader);
                    VuoShader_addSource(shader, VuoMesh_IndividualTriangles, NULL, NULL, fragmentShader);
                    VuoShader_setUniform_VuoImage(shader, "cocgsy_src", dxtImage[0]);
                    image = VuoImageRenderer_render(shader, dxtImage[0]->pixelsWide, dxtImage[0]->pixelsHigh, VuoImageColorDepth_8);
                    VuoRelease(shader);
                }
                else if (hapFrame.codecSubType == kHapYCoCgACodecSubType)
                {
                    // Based on https://github.com/Vidvox/hap-in-avfoundation/blob/master/HapInAVF%20Test%20App/ScaledCoCgYPlusAToRGBA.frag
                    static const char *fragmentShader = VUOSHADER_GLSL_SOURCE(120,
                        uniform sampler2D cocgsy_src;
                        uniform sampler2D alpha_src;
                        const vec4 offsets = vec4(-0.50196078431373, -0.50196078431373, 0.0, 0.0);
                        varying vec2 fragmentTextureCoordinate;
                        void main()
                        {
                            vec2 tc = vec2(fragmentTextureCoordinate.x, 1. - fragmentTextureCoordinate.y);
                            vec4 CoCgSY = texture2D(cocgsy_src, tc);
                            float alpha = texture2D(alpha_src, tc).r;
 
                            CoCgSY += offsets;
 
                            float scale = ( CoCgSY.z * ( 255.0 / 8.0 ) ) + 1.0;
 
                            float Co = CoCgSY.x / scale;
                            float Cg = CoCgSY.y / scale;
                            float Y = CoCgSY.w;
 
                            gl_FragColor = vec4(Y + Co - Cg, Y + Cg, Y - Co - Cg, alpha);
                        }
                    );
 
                    VuoShader shader = VuoShader_make("YCoCg+A to RGBA Shader");
                    VuoRetain(shader);
                    VuoShader_addSource(shader, VuoMesh_IndividualTriangles, NULL, NULL, fragmentShader);
                    VuoShader_setUniform_VuoImage(shader, "cocgsy_src", dxtImage[0]);
                    VuoShader_setUniform_VuoImage(shader, "alpha_src", dxtImage[1]);
                    image = VuoImageRenderer_render(shader, dxtImage[0]->pixelsWide, dxtImage[0]->pixelsHigh, VuoImageColorDepth_8);
                    VuoRelease(shader);
                }
                else
                {
                    VUserLog("Error: Unknown codecSubType '%s'.", VuoOsStatus_getText(hapFrame.codecSubType));
                    return;
                }
            });
 
            [hapFrame release];
 
            if (!image)
                return false;
        }
        else
        {
            // For non-Hap frames, AV Foundation can directly give us an OpenGL texture.
 
            CMSampleBufferRef sampleBuffer = [assetReaderVideoTrackOutput copyNextSampleBuffer];
 
            if (!sampleBuffer)
                return false;
 
            timestamp = CMTimeGetSeconds(CMSampleBufferGetPresentationTimeStamp(sampleBuffer));
            duration  = CMTimeGetSeconds(CMSampleBufferGetDuration(sampleBuffer));
            if (isnan(duration))
                duration = 1./nominalFrameRate;
 
            CVPixelBufferRef buffer = (CVPixelBufferRef) CMSampleBufferGetImageBuffer(sampleBuffer);
            if (!buffer)
            {
                CMSampleBufferInvalidate(sampleBuffer);
                CFRelease(sampleBuffer);
                return false;
            }
 
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
            __block CVOpenGLTextureRef texture;
            __block CVReturn ret;
            VuoGlContext_perform(^(CGLContextObj cgl_ctx){
                ret = CVOpenGLTextureCacheCreateTextureFromImage(NULL, textureCache, buffer, NULL, &texture);
            });
            if (ret != kCVReturnSuccess)
            {
                char *error = VuoOsStatus_getText(ret);
                VUserLog("Error: Couldn't convert CVImageBuffer to texture: %s", error);
                free(error);
                CMSampleBufferInvalidate(sampleBuffer);
                CFRelease(sampleBuffer);
                return false;
            }
            VuoImage rectImage = VuoImage_makeClientOwnedGlTextureRectangle(
                        CVOpenGLTextureGetName(texture),
                        hasAlpha ? GL_RGBA : GL_RGB,
                        CVPixelBufferGetWidth(buffer),
                        CVPixelBufferGetHeight(buffer),
                        VuoAvPlayerObject_freeCallback, NULL);
            VuoRetain(rectImage);
            image = VuoImage_makeCopy(rectImage, CVOpenGLTextureIsFlipped(texture), 0, 0, false);
            CVOpenGLTextureRelease(texture);
            VuoRelease(rectImage);
            VuoGlContext_perform(^(CGLContextObj cgl_ctx){
                CVOpenGLTextureCacheFlush(textureCache, 0);
            });
#pragma clang diagnostic pop
 
            CMSampleBufferInvalidate(sampleBuffer);
            CFRelease(sampleBuffer);
        }
 
        VuoVideoFrame* frame = (VuoVideoFrame*) malloc(sizeof(VuoVideoFrame));
        *frame = VuoVideoFrame_make(image, timestamp, duration);
        VuoVideoFrame_retain(*frame);
        NSValue* val = [NSValue valueWithPointer:frame];
        [videoQueue addObject:val];
 
        return true;
    }
    else if ([assetReader status] == AVAssetReaderStatusFailed)
    {
        VUserLog("Error: AVAssetReader failed: %s. %s.",
                 [[[assetReader error] localizedDescription] UTF8String],
                 [[[assetReader error] localizedFailureReason] UTF8String]);
        return false;
    }
    else
    {
        VUserLog("Error: AVAssetReader status %ld", [assetReader status]);
        return false;
    }
}
 
- (bool) copyNextAudioSampleBuffer
{
    if([assetReader status] == AVAssetReaderStatusReading)
    {
        CMSampleBufferRef audioSampleBuffer = [assetReaderAudioTrackOutput copyNextSampleBuffer];
 
        audioBufferSampleIndex = 0;
 
        if(audioSampleBuffer == NULL)
        {
            audioBufferSamplesPerChannel = 0;
            return false;
        }
 
        // CMItemCount numSamplesInAudioBuffer = CMSampleBufferGetNumSamples(audioSampleBuffer);
        audioTimestamp = CMTimeGetSeconds(CMSampleBufferGetPresentationTimeStamp(audioSampleBuffer));
 
        CMBlockBufferRef audioBlockBuffer = CMSampleBufferGetDataBuffer( audioSampleBuffer );
        // AudioBufferList audioBufferList;
 
        size_t bufferSize = 0;
 
        CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(
            audioSampleBuffer,
            &bufferSize,
            NULL,
            0,
            NULL,
            NULL,
            0,
            NULL
        );
 
        AudioBufferList* audioBufferList = malloc(bufferSize);
 
        OSStatus err = CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(
            audioSampleBuffer,
            NULL,
            audioBufferList,
            bufferSize,
            NULL,
            NULL,
            kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment,
            &audioBlockBuffer
        );
 
        if(err != 0)
        {
            VUserLog("AvFoundation failed extracting audio buffer: %i", err);
 
            audioBufferSamplesPerChannel = 0;
            free(audioBufferList);
            CFRelease(audioBlockBuffer);
            CFRelease(audioSampleBuffer);
 
            return false;
        }
 
        // CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(
        //  audioSampleBuffer,
        //  NULL,
        //  &audioBufferList,
        //  sizeof(audioBufferList),
        //  NULL,
        //  NULL,
        //  kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment,
        //  &audioBlockBuffer);
 
        // I haven't been able to find anything about when multiple buffers would be used.  In every format
        // so far there's only ever one, with channels interleaved in mData.  I wasn't sure whether multiple
        // buffers would mean additional channels, or more data for the same channels, or a different track
        // entirely.  So for now just look at the first buffer and check here first when something inevitably
        // goes wrong.
 
        // for (int curBuffer = 0; curBuffer < audioBufferList.mNumberBuffers; curBuffer++)
        const int curBuffer = 0;
 
        audioBufferChannelCount = audioBufferList->mBuffers[curBuffer].mNumberChannels;
        size_t dataByteSize = audioBufferList->mBuffers[curBuffer].mDataByteSize;
        audioBufferSamplesPerChannel = (dataByteSize / sizeof(Float32)) / audioBufferChannelCount;
 
        if( dataByteSize > audioBufferCapacity )
        {
            if (!(audioBuffer = realloc(audioBuffer, dataByteSize)))
            {
                free(audioBufferList);
                CFRelease(audioBlockBuffer);
                CFRelease(audioSampleBuffer);
                audioBufferSamplesPerChannel = 0;
                VUserLog("AvFoundation video decoder is out of memory.");
                return false;
            }
 
            audioBufferCapacity = dataByteSize;
        }
 
        Float32* samples = (Float32 *)audioBufferList->mBuffers[curBuffer].mData;
        memcpy(audioBuffer, samples, audioBufferList->mBuffers[curBuffer].mDataByteSize);
 
        free(audioBufferList);
        CFRelease(audioBlockBuffer);
        CFRelease(audioSampleBuffer);
 
 
        // Sometimes AVFoundation says the movie has a certain number of audio channels,
        // but actually decodes a different number of audio channels.
        // https://b33p.net/kosada/node/12952
        if (audioChannelCount != audioBufferChannelCount)
        {
            VUserLog("Warning: AVFoundation reported %d audio channel%s, but actually decoded %d channel%s.",
                     audioChannelCount, audioChannelCount == 1 ? "" : "s",
                     audioBufferChannelCount, audioBufferChannelCount == 1 ? "" : "s");
            audioChannelCount = audioBufferChannelCount;
        }
 
        return true;
    }
    return false;
}
 
@end