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Convert remote GIF into something MPMoviePlayerController can use
//
// GIFDownloader.h
// TheJoysOfCode
//
// Created by Bob on 29/10/12.
// Copyright (c) 2012 Tall Developments. All rights reserved.
//
#import <Foundation/Foundation.h>
FOUNDATION_EXTERN NSString * const kGIF2MP4ConversionErrorDomain;
typedef enum {
kGIF2MP4ConversionErrorInvalidGIFImage = 0,
kGIF2MP4ConversionErrorAlreadyProcessing,
kGIF2MP4ConversionErrorBufferingFailed,
kGIF2MP4ConversionErrorInvalidResolution,
kGIF2MP4ConversionErrorTimedOut,
} kGIF2MP4ConversionError;
typedef void (^kGIF2MP4ConversionCompleted) (NSString* outputFilePath, NSError* error);
@interface GIFDownloader : NSObject
+ (void) sendAsynchronousRequest: (NSString*) srcPath
downloadFilePath: (NSString*) filePath
thumbnailFilePath: (NSString*) thumbFilePath
completed: (kGIF2MP4ConversionCompleted) handler;
@end
//
// GIFDownloader.m
// TheJoysOfCode
//
// Created by Bob on 29/10/12.
// Copyright (c) 2012 Tall Developments. All rights reserved.
//
#import "GIFDownloader.h"
#import <AVFoundation/AVFoundation.h>
#import <ImageIO/ImageIO.h>
#import <MobileCoreServices/MobileCoreServices.h>
#define FPS 30
NSString * const kGIF2MP4ConversionErrorDomain = @"GIF2MP4ConversionError";
@implementation GIFDownloader
+ (NSOperationQueue*) requestQueue {
static NSOperationQueue* requestQueue = nil;
if( !requestQueue ) {
requestQueue = [NSOperationQueue new];
requestQueue.maxConcurrentOperationCount = 5;
}
return requestQueue;
}
static __strong NSMutableArray* requests = nil;
+ (BOOL) queueContainsRequest: (NSURLRequest*) request {
if( !requests ) {
requests = [NSMutableArray new];
}
return [requests containsObject: request.URL.absoluteString];
}
+ (void) removeRequest: (NSURLRequest*) request {
[requests removeObject: request.URL.absoluteString];
}
+ (void) addRequest: (NSURLRequest*) request {
[requests addObject: request.URL.absoluteString];
}
+ (void) sendAsynchronousRequest: (NSString*) srcURLPath
downloadFilePath: (NSString*) filePath
thumbnailFilePath: (NSString *)thumbFilePath
completed: (kGIF2MP4ConversionCompleted)handler {
if( !srcURLPath )
return;
if( !filePath )
return;
if( !handler )
return;
NSParameterAssert(srcURLPath);
NSParameterAssert(filePath);
NSParameterAssert(handler);
NSURL* URL = [NSURL URLWithString: srcURLPath];
NSURLRequest* request = [NSURLRequest requestWithURL: URL];
if( [self queueContainsRequest: request] ) {
NSError* error = [NSError errorWithDomain: kGIF2MP4ConversionErrorDomain
code: kGIF2MP4ConversionErrorAlreadyProcessing
userInfo: nil];
handler(filePath, error);
return;
}
[self addRequest: request];
[[self requestQueue] addOperationWithBlock: ^{
#if DEBUG
NSLog(@"Start writing: %@", filePath.lastPathComponent);
#endif
//NSURLResponse* response = nil;
NSError* error = nil;
NSData* data = [NSURLConnection sendSynchronousRequest: request
returningResponse: NULL
error: &error];
if( error ) {
[self queueContainsRequest: request];
handler(filePath, error);
}
else {
if( [[NSFileManager defaultManager] fileExistsAtPath: filePath] ) {
[[NSFileManager defaultManager] removeItemAtPath: filePath
error: &error];
if( error ) {
[self queueContainsRequest: request];
handler(filePath, error);
}
}
NSURL* outFilePath = [NSURL fileURLWithPath: filePath];
kGIF2MP4ConversionCompleted completionHandler = ^(NSString* path, NSError* error) {
[self removeRequest: request];
dispatch_async(dispatch_get_main_queue(), ^{
handler(path, error);
});
};
[self processGIFData: data toFilePath: outFilePath thumbFilePath: thumbFilePath completed: completionHandler];
}
#if DEBUG
NSLog(@"Finish writing: %@", filePath.lastPathComponent);
#endif
}];
}
+ (BOOL) processGIFData: (NSData*) data
toFilePath: (NSURL*) outFilePath
thumbFilePath: (NSString*) thumbFilePath
completed: (kGIF2MP4ConversionCompleted) completionHandler {
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
unsigned char *bytes = (unsigned char*)data.bytes;
NSError* error = nil;
if( !CGImageSourceGetStatus(source) == kCGImageStatusComplete ) {
error = [NSError errorWithDomain: kGIF2MP4ConversionErrorDomain
code: kGIF2MP4ConversionErrorInvalidGIFImage
userInfo: nil];
CFRelease(source);
completionHandler(outFilePath.absoluteString, error);
return NO;
}
size_t sourceWidth = bytes[6] + (bytes[7]<<8), sourceHeight = bytes[8] + (bytes[9]<<8);
//size_t sourceFrameCount = CGImageSourceGetCount(source);
__block size_t currentFrameNumber = 0;
__block Float64 totalFrameDelay = 0.f;
AVAssetWriter* videoWriter = [[AVAssetWriter alloc] initWithURL: outFilePath
fileType: AVFileTypeQuickTimeMovie
error: &error];
if( error ) {
CFRelease(source);
completionHandler(outFilePath.absoluteString, error);
return NO;
}
if( sourceWidth > 640 || sourceWidth == 0) {
CFRelease(source);
error = [NSError errorWithDomain: kGIF2MP4ConversionErrorDomain
code: kGIF2MP4ConversionErrorInvalidResolution
userInfo: nil];
completionHandler(outFilePath.absoluteString, error);
return NO;
}
if( sourceHeight > 480 || sourceHeight == 0 ) {
CFRelease(source);
error = [NSError errorWithDomain: kGIF2MP4ConversionErrorDomain
code: kGIF2MP4ConversionErrorInvalidResolution
userInfo: nil];
completionHandler(outFilePath.absoluteString, error);
return NO;
}
size_t totalFrameCount = CGImageSourceGetCount(source);
size_t thumbnailFrameCount = floorf( totalFrameCount * 0.05 );
if( totalFrameCount <= 0 ) {
CFRelease(source);
error = [NSError errorWithDomain: kGIF2MP4ConversionErrorDomain
code: kGIF2MP4ConversionErrorInvalidGIFImage
userInfo: nil];
completionHandler(outFilePath.absoluteString, error);
return NO;
}
NSAssert(sourceWidth <= 640, @"%lu is too wide for a video", sourceWidth);
NSAssert(sourceHeight <= 480, @"%lu is too tall for a video", sourceHeight);
NSDictionary *videoSettings = @{
AVVideoCodecKey : AVVideoCodecH264,
AVVideoWidthKey : @(sourceWidth),
AVVideoHeightKey : @(sourceHeight)
};
AVAssetWriterInput* videoWriterInput = [AVAssetWriterInput assetWriterInputWithMediaType: AVMediaTypeVideo
outputSettings: videoSettings];
videoWriterInput.expectsMediaDataInRealTime = YES;
NSAssert([videoWriter canAddInput: videoWriterInput], @"Video writer can not add video writer input");
[videoWriter addInput: videoWriterInput];
NSDictionary* attributes = @{
(NSString*)kCVPixelBufferPixelFormatTypeKey : @(kCVPixelFormatType_32ARGB),
(NSString*)kCVPixelBufferWidthKey : @(sourceWidth),
(NSString*)kCVPixelBufferHeightKey : @(sourceHeight),
(NSString*)kCVPixelBufferCGImageCompatibilityKey : @YES,
(NSString*)kCVPixelBufferCGBitmapContextCompatibilityKey : @YES
};
AVAssetWriterInputPixelBufferAdaptor* adaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput: videoWriterInput
sourcePixelBufferAttributes: attributes];
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime: CMTimeMakeWithSeconds(totalFrameDelay, FPS)];
while(1) {
if( videoWriterInput.isReadyForMoreMediaData ) {
#if DEBUG
//NSLog(@"Drawing frame %lu/%lu", currentFrameNumber, totalFrameCount);
#endif
NSDictionary* options = @{(NSString*)kCGImageSourceTypeIdentifierHint : (id)kUTTypeGIF};
CGImageRef imgRef = CGImageSourceCreateImageAtIndex(source, currentFrameNumber, (__bridge CFDictionaryRef)options);
if( imgRef ) {
CFDictionaryRef properties = CGImageSourceCopyPropertiesAtIndex(source, currentFrameNumber, NULL);
CFDictionaryRef gifProperties = CFDictionaryGetValue(properties, kCGImagePropertyGIFDictionary);
//Save our thumbnail
if( thumbnailFrameCount == currentFrameNumber ) {
if( [[NSFileManager defaultManager] fileExistsAtPath: thumbFilePath] ) {
[[NSFileManager defaultManager] removeItemAtPath: thumbFilePath error: nil];
}
UIImage* img = [UIImage imageWithCGImage: imgRef];
[UIImagePNGRepresentation(img) writeToFile: thumbFilePath atomically: YES];
}
if( gifProperties ) {
CVPixelBufferRef pxBuffer = [self newBufferFrom: imgRef
withPixelBufferPool: adaptor.pixelBufferPool
andAttributes: adaptor.sourcePixelBufferAttributes];
if( pxBuffer ) {
NSNumber* delayTime = CFDictionaryGetValue(gifProperties, kCGImagePropertyGIFDelayTime);
totalFrameDelay += delayTime.floatValue;
CMTime time = CMTimeMakeWithSeconds(totalFrameDelay, FPS);
if( ![adaptor appendPixelBuffer: pxBuffer withPresentationTime: time] ) {
TFLog(@"Could not save pixel buffer!: %@", videoWriter.error);
CFRelease(properties);
CGImageRelease(imgRef);
CVBufferRelease(pxBuffer);
break;
}
CVBufferRelease(pxBuffer);
}
}
if( properties ) CFRelease(properties);
CGImageRelease(imgRef);
currentFrameNumber++;
}
else {
//was no image returned -> end of file?
[videoWriterInput markAsFinished];
void (^videoSaveFinished)(void) = ^{
completionHandler(outFilePath.absoluteString, nil);
};
if( [videoWriter respondsToSelector: @selector(finishWritingWithCompletionHandler:)]) {
[videoWriter finishWritingWithCompletionHandler: videoSaveFinished];
}
else {
[videoWriter finishWriting];
videoSaveFinished();
}
break;
}
}
else {
//NSLog(@"Was not ready...");
[NSThread sleepForTimeInterval: 0.1];
}
};
CFRelease(source);
return YES;
};
+ (CVPixelBufferRef) newBufferFrom: (CGImageRef) frame
withPixelBufferPool: (CVPixelBufferPoolRef) pixelBufferPool
andAttributes: (NSDictionary*) attributes {
NSParameterAssert(frame);
size_t width = CGImageGetWidth(frame);
size_t height = CGImageGetHeight(frame);
size_t bpc = 8;
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CVPixelBufferRef pxBuffer = NULL;
CVReturn status = kCVReturnSuccess;
if( pixelBufferPool )
status = CVPixelBufferPoolCreatePixelBuffer(kCFAllocatorDefault, pixelBufferPool, &pxBuffer);
else {
status = CVPixelBufferCreate(kCFAllocatorDefault, width, height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef)attributes, &pxBuffer);
}
NSAssert(status == kCVReturnSuccess, @"Could not create a pixel buffer");
CVPixelBufferLockBaseAddress(pxBuffer, 0);
void *pxData = CVPixelBufferGetBaseAddress(pxBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(pxBuffer);
CGContextRef context = CGBitmapContextCreate(pxData,
width,
height,
bpc,
bytesPerRow,
colorSpace,
kCGImageAlphaNoneSkipFirst);
NSAssert(context, @"Could not create a context");
CGContextDrawImage(context, CGRectMake(0, 0, width, height), frame);
CVPixelBufferUnlockBaseAddress(pxBuffer, 0);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
return pxBuffer;
}
@end
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