Question

我无法从ALAsset

获取的网址中检索NSData

以下是我尝试过的代码： - 我总是将NSData视为零。

 NSData *webData = [NSData dataWithContentsOfURL:[asset defaultRepresentation].url];

我也试过这样的事情

 NSData *webData1 = [NSData dataWithContentsOfURL:[[asset valueForProperty:ALAssetPropertyURLs] valueForKey:[[[asset valueForProperty:ALAssetPropertyURLs] allKeys] objectAtIndex:0]]];

我从ALAsset获得的网址： -

？

资产库：//asset/asset.MOV ID = 1000000116＆安培; EXT = MOV

我已经尝试过以下链接，但是我需要不必要地写入一个非常耗时的临时位置。

Getting video from ALAsset

任何正确方向的提示都将受到高度赞赏。

等待你的回复

Answer 1

试试这段代码： -

ALAssetRepresentation *rep = [asset defaultRepresentation];
Byte *buffer = (Byte*)malloc((NSUInteger)rep.size);
NSUInteger buffered = [rep getBytes:buffer fromOffset:0.0 length:(NSUInteger)rep.size error:nil];
NSData *data = [NSData dataWithBytesNoCopy:buffer length:buffered freeWhenDone:YES];

Answer 2

字节缓冲区=（字节）malloc（rep.size）;如果rep.size是如此之大，可能是300M，那将会崩溃。所以试试这段代码：

+ (BOOL)writeDataToPath:(NSString*)filePath andAsset:(ALAsset*)asset
{
    [[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil];
    NSFileHandle *handle = [NSFileHandle fileHandleForWritingAtPath:filePath];
    if (!handle) {
        return NO;
    }
    static const NSUInteger BufferSize = 1024*1024;

    ALAssetRepresentation *rep = [asset defaultRepresentation];
    uint8_t *buffer = calloc(BufferSize, sizeof(*buffer));
    NSUInteger offset = 0, bytesRead = 0;

    do {
        @try {
            bytesRead = [rep getBytes:buffer fromOffset:offset length:BufferSize error:nil];
            [handle writeData:[NSData dataWithBytesNoCopy:buffer length:bytesRead freeWhenDone:NO]];
            offset += bytesRead;
        } @catch (NSException *exception) {
            free(buffer);

            return NO;
        }
    } while (bytesRead > 0);

    free(buffer);
    return YES;
}

从ALAsset url iOS获取视频NSData

2 个答案: