VTDecompressionSessionDecodeFrame失敗，代碼爲-kVTVideoDecoderBadDataErr

我一直在嘗試使用VTDecompressionSessionDecodeFrame解碼H264，但得到錯誤。參數集已被創建並且看起來很好，到目前爲止沒有任何錯誤，所以它可能與我對CMSampleBufferRef中定時信息的理解有關。任何投入將不勝感激VTDecompressionSessionDecodeFrame失敗，代碼爲-kVTVideoDecoderBadDataErr

void didDecompress(void *decompressionOutputRefCon, void *sourceFrameRefCon, OSStatus status, VTDecodeInfoFlags infoFlags, CVImageBufferRef imageBuffer, CMTime presentationTimeStamp, CMTime presentationDuration){ 

    NSLog(@"In decompression callback routine");

}

void decodeH264 { 

VTDecodeInfoFlags infoFlags; 
[NALPacket appendBytes: NalPacketSize length:4]; 
        [NALPacket appendBytes: &NALCODE length:1]; 
        [NALPacket appendBytes: startPointer length:buflen]; 
        void *samples = (void *)[NALTestPacket bytes]; 

        blockBuffer = NULL; 

        // add the nal raw data to the CMBlockBuffer 
        status = CMBlockBufferCreateWithMemoryBlock(
                   kCFAllocatorDefault, 
                   samples, 
                   [NALPacket length], 
                   kCFAllocatorDefault, 
                   NULL, 
                   0, 
                   [NALPacket length], 
                   0, 
                   &blockBuffer); 

         const size_t * samplesizeArrayPointer; 
         size_t sampleSizeArray= buflen; 
         samplesizeArrayPointer = &sampleSizeArray; 

         int32_t timeSpan = 1000000; 
         CMTime PTime = CMTimeMake(presentationTime, timeSpan); 
         CMSampleTimingInfo timingInfo; 
         timingInfo.presentationTimeStamp = PTime; 
         timingInfo.duration = kCMTimeZero; 
         timingInfo.decodeTimeStamp = kCMTimeInvalid; 

         status = CMSampleBufferCreate(kCFAllocatorDefault, blockBuffer, YES, NULL, NULL, formatDescription, 1, 1, &timingInfo, 0, samplesizeArrayPointer, &sampleBuffer); 

         CFArrayRef attachmentsArray = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, true); 
         for (CFIndex i = 0; i < CFArrayGetCount(attachmentsArray); ++i) { 
          CFMutableDictionaryRef attachments = (CFMutableDictionaryRef)CFArrayGetValueAtIndex(attachmentsArray, i); 
          CFDictionarySetValue(attachments, kCMSampleAttachmentKey_DoNotDisplay, kCFBooleanFalse); 
          CFDictionarySetValue(attachments, kCMSampleAttachmentKey_DisplayImmediately, kCFBooleanTrue); 
         } 

// I Frame 
         status = VTDecompressionSessionDecodeFrame(decoder, sampleBuffer, kVTDecodeFrame_1xRealTimePlayback, (void*)CFBridgingRetain(currentTime), &infoFlags); 
         if (status != noErr) { 
          NSLog(@"Decode error"); 
         }

來源

2014-09-26 Md1079

發現爲什麼這是行不通的，我忘了設定CMSampleBufferRef每一個新的樣本被抓獲的時間爲NULL。

samples = NULL; 

status = CMSampleBufferCreate(kCFAllocatorDefault, blockBuffer, YES, NULL, NULL, formatDescription, 1, 1, &timingInfo, 0, samplesizeArrayPointer, &sampleBuffer);

來源

2014-09-29 08:19:15 Md1079

請您詳細說明一下嗎？我從VTDecompressionSessionDecodeFrame（）獲得相同的返回值，但是我無法從您的評論中判斷出您需要做什麼來避免此錯誤返回。謝謝！ – rpj 2014-10-14 00:34:54

不幸的是，我不能，這是我的一些嘗試和錯誤。我正在通過網絡解碼一個比特流，每當我得到一個新的nal單元並在一個採樣緩衝區中準備它時，我需要將先前使用的採樣緩衝區設置爲NULL。有趣的是，我已經停止使用VTDecompressionDecodeFrame，並使用AVSampleBufferDisplayLayer，它在你的應用程序的圖層中顯示H264的效果很好。 – Md1079 2014-10-14 11:29:19

聽起來像你的問題與幀緩衝區的內存管理有關，最終也是我的問題。謝謝你的提示！ – rpj 2014-11-20 01:49:42

VTDecompressionSessionDecodeFrame失敗，代碼爲-kVTVideoDecoderBadDataErr

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