因此，我构建了一个图片和视频部分上传系统，该系统似乎工作正常，直到我们尝试压缩视频或用户尝试播放视频。我发现编写视频的字节并不像附加字节那么简单...我现在(稍微)熟悉原子(free、mov、mdat、uuid 等)等概念，并且想知道为什么以及如何video 只是附加到新文件的字节集合，无法识别即使所有字节都已写入，原子仍然存在。
无论如何，这里有一些源代码:
服务器端我们有一个部分上传对象:
public class PartialUpload {
private Integer partialUploadId;
private String urlSuffix;
private Date dateAdded;
private Long expiresIn;
private Long currentBytesMin;
private Long currentBytesMax;
private Long totalBytes;
private Boolean complete;
private String filename;
//there are getters and setters which bind to a database entity below but these are the fields
}
在服务器端，我们还有以下方法来检查部分上传是否已开始、正在继续或已达到其总字节数。
@RequestMapping(value = "/video_partial", method = RequestMethod.POST)
public ResponseEntity<?> postVideoPartial(@RequestParam("name") String name, @RequestParam(name = "totalBytes") Long totalBytes) throws IOException {
PartialUpload upload = new PartialUpload();
upload.setUrlSuffix(upload.hashUrlSuffix()); // creates a url friendly hash
Calendar expiry = Calendar.getInstance();
upload.setDateAdded(expiry.getTime());
expiry.add(Calendar.DAY_OF_MONTH, PARTIAL_UPLOAD_EXPIRY_TIME); // constant which is a day
upload.setExpiresIn(expiry.getTimeInMillis() - Calendar.getInstance().getTimeInMillis());
upload.setComplete(false);
upload.setFilename(name);
upload.setTotalBytes(totalBytes);
partialUploadRepo.save(upload); //save this object to the database
PartialUploadInitialDTO dto = new PartialUploadInitialDTO(); //initial DTO which contains the url suffix and the time it expires in
dto.expiresIn = upload.getExpiresIn();
dto.urlSuffix = upload.getUrlSuffix();
return new ResponseEntity<>(dto, HttpStatus.ACCEPTED);
}
//continuing the partial upload until complete
@RequestMapping(value = "/video_partial/{urlSuffix}", method = RequestMethod.POST)
public ResponseEntity<?> postVideoPartial(@RequestBody byte[] partialBytes, @PathVariable("urlSuffix") String urlSuffix) throws IOException {
try {
PartialUpload upload = partialUploadRepo.getUploadByUrlSuffix(urlSuffix);
if (!upload.isExpired()) {
if (upload.getComplete() != null && upload.getComplete()) {
return new ResponseEntity<>("Upload already complete", HttpStatus.BAD_REQUEST);
} else {
if (upload.getCurrentBytesMin() == null) { //tests if the very first chunk has been sent. If null, the chunk has yet to be sent
upload.setCurrentBytesMin(0L); //Tells the client to start at a 0 offset
upload.setCurrentBytesMax(START_BYTES_MAX); //Tells the client to upload bytes to the maximum... if there are fewer bytes than the maximum only the applicable bytes will be written
if (MediaHelper.initialFileWrite(partialBytes, upload, MediaType.VIDEO)) { //instantiates the file and writes bytes given the file does not yet exist
if (upload.getCurrentBytesMax() >= upload.getTotalBytes()) { // if the total bytes have been written
if (MediaHelper.moveFileToTempFolder(upload, MediaType.VIDEO)) { //moves the file for compression
PartialUploadCompleteDTO completeDTO = new PartialUploadCompleteDTO();
completeDTO.success = true;
upload.setCurrentBytesMin(upload.getTotalBytes());
upload.setCurrentBytesMax(upload.getTotalBytes());
upload.setComplete(true);
partialUploadRepo.save(upload); //saves that the upload has been completed
return new ResponseEntity<>(completeDTO, HttpStatus.OK); //return success
} else {
return new ResponseEntity<>("Couldn't Move File To Temp Folder", HttpStatus.INTERNAL_SERVER_ERROR);
}
} else {
//***************************************
PartialUploadInProgressDTO dto = new PartialUploadInProgressDTO(); //case where there are more chunks to upload and where I am receiving error
Calendar expiry = Calendar.getInstance();
expiry.setTime(upload.getDateAdded());
expiry.setTimeInMillis(expiry.getTimeInMillis() + upload.getExpiresIn());
dto.expirationDateTime = expiry.getTime();
dto.nextExpectedMin = upload.getCurrentBytesMax() + 1; //offset the next bytes by the last byte written + 1 MAY BE THE CAUSE OF THE ERRORS
dto.nextExpectedMax = upload.getCurrentBytesMax() + (upload.getCurrentBytesMax() - upload.getCurrentBytesMin()); // offset the next max by the current max (which is the minimum) plus the interval number of bytes
if (dto.nextExpectedMax >= upload.getTotalBytes()) { //if the max overshoots the total bytes make the max the new total bytes
dto.nextExpectedMax = upload.getTotalBytes();
}
upload.setCurrentBytesMin(dto.nextExpectedMin);
upload.setCurrentBytesMax(dto.nextExpectedMax);
partialUploadRepo.save(upload); // saves the next expected chunk
return new ResponseEntity<>(dto, HttpStatus.ACCEPTED);
}
} else {
return new ResponseEntity<>("Retry", HttpStatus.BAD_REQUEST);
}
} else {
//appends bytes to the already existing file
if (MediaHelper.appendBytesToFile(upload, partialBytes, MediaType.VIDEO)) {
if (upload.getCurrentBytesMax() >= upload.getTotalBytes()) { //test if complete (total bytes achieved)
if (MediaHelper.moveFileToTempFolder(upload, MediaType.VIDEO)) {
PartialUploadCompleteDTO completeDTO = new PartialUploadCompleteDTO();
completeDTO.success = true;
upload.setCurrentBytesMin(upload.getTotalBytes());
upload.setCurrentBytesMax(upload.getTotalBytes());
upload.setComplete(true);
partialUploadRepo.save(upload); //see above
return new ResponseEntity<>(completeDTO, HttpStatus.OK);
} else {
return new ResponseEntity<>("Couldn't Move File To Temp Folder", HttpStatus.INTERNAL_SERVER_ERROR);
}
} else {
PartialUploadInProgressDTO dto = new PartialUploadInProgressDTO();
Calendar expiry = Calendar.getInstance();
expiry.setTime(upload.getDateAdded());
expiry.setTimeInMillis(expiry.getTimeInMillis() + upload.getExpiresIn());
dto.expirationDateTime = expiry.getTime();
dto.nextExpectedMin = upload.getCurrentBytesMax() + 1;
dto.nextExpectedMax = upload.getCurrentBytesMax() + (upload.getCurrentBytesMax() - upload.getCurrentBytesMin());
if (dto.nextExpectedMax >= upload.getTotalBytes()) {
dto.nextExpectedMax = upload.getTotalBytes();
}
upload.setCurrentBytesMin(dto.nextExpectedMin);
upload.setCurrentBytesMax(dto.nextExpectedMax);
partialUploadRepo.save(upload);
return new ResponseEntity<>(dto, HttpStatus.ACCEPTED);
}
} else {
return new ResponseEntity<>("Retry", HttpStatus.BAD_REQUEST);
}
}
}
} else {
return new ResponseEntity<>("Upload has expired", HttpStatus.BAD_REQUEST);
}
} catch(Exception e) {
return new ResponseEntity<>("No File Exists At URL", HttpStatus.BAD_REQUEST);
}
}
这些是媒体帮助器方法:
public boolean initialFileWrite(byte[] partialBytes, PartialUpload upload, MediaType type) {
File blobUploadDirectory = null;
try {
if (type == MediaType.IMAGE) {
blobUploadDirectory = getBlobImageUploadDir();
} else {
blobUploadDirectory = getBlobVideoUploadDir();
}
if (!blobUploadDirectory.exists()) {
blobUploadDirectory.mkdirs();
}
File file = new File(blobUploadDirectory.getAbsolutePath() + "/" + upload.getFilename());
if (!file.exists()) {
file.createNewFile();
}
FileUtils.writeByteArrayToFile(file, partialBytes, false);
return true;
} catch(Exception e) {
//unappend appended bytes
e.printStackTrace();
return false;
}
}
public boolean appendBytesToFile(PartialUpload upload, byte[] partialBytes, MediaType type) {
File blobUploadDirectory = null;
try {
if (type == MediaType.IMAGE) {
blobUploadDirectory = getBlobImageUploadDir();
} else {
blobUploadDirectory = getBlobVideoUploadDir();
}
if (!blobUploadDirectory.exists()) {
blobUploadDirectory.mkdirs();
}
File file = new File(blobUploadDirectory.getAbsolutePath() + "/" + upload.getFilename());
if (!file.exists()) {
file.createNewFile();
}
FileUtils.writeByteArrayToFile(file, partialBytes, true);
return true;
} catch(Exception e) {
//unappend appended bytes
e.printStackTrace();
return false;
}
}
public boolean moveFileToTempFolder(PartialUpload upload, MediaType type) {
File blobUploadDirectory = null;
try {
if (type == MediaType.IMAGE) {
blobUploadDirectory = getBlobImageUploadDir();
} else {
blobUploadDirectory = getBlobVideoUploadDir();
}
if (!blobUploadDirectory.exists()) {
blobUploadDirectory.mkdirs();
return false;
}
File file = new File(blobUploadDirectory.getAbsolutePath() + "/" + upload.getFilename());
if (!file.exists()) {
return false;
}
File outFile = type == MediaType.IMAGE ? new File(getLocalImageUploadDir(), upload.getFilename()) : new File(getLocalVideoUploadDir(), upload.getFilename());
return file.renameTo(outFile);
} catch(Exception e) {
//unappend appended bytes
return false;
}
}
在移动应用程序中，我使用 QTFastStart 的修改版本将 moov 原子移动到结构的前面(不是必需的，但这是一个临时解决方案)。否则 moov 原子就会被损坏。任何关于为什么原子在文件传输过程中被损坏的帮助将不胜感激。
这里是 Android 应用程序的更多源代码
if (currentMedia.getType() == VIDEO) {
try {
String newFileName = currentMedia.getPath(); //qualified media path
newFileName = newFileName.replaceAll("\\d+\\.mp4", "newFile.mp4"); //makes a temp mp4 for the current media. I tested with AtomicParsley and QTFastStart (PY) to make sure this wasn't the issue
File inFile = new File(currentMedia.getPath());
File outFile = new File(newFileName);
if (!outFile.exists()) {
outFile.createNewFile();
}
QtFastStart.fastStart(inFile, outFile); //moves the moov atom indices
outFile.renameTo(new File(currentMedia.getPath())); //makes the original file the moved file
file = new File(currentMedia.getPath());
} catch (IOException e) {
e.printStackTrace();
} catch (QtFastStart.MalformedFileException e) {
e.printStackTrace();
} catch (QtFastStart.UnsupportedFileException e) {
e.printStackTrace();
}
} else {
file = new File(currentMedia.getPath());
}
//reads a total number of bytes from a file
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
fileContent = Files.readAllBytes(file.toPath());
} else {
fileContent = readFile(file);
}
if (currentMedia.getType() == IMAGE) {
mediaApiFactory.makeRequestStartImagePartialUpload(file.getName(), fileContent.length).start(null, initialResultListener);
pictureProgressText.setText("Uploading " + currentMedia.getName() + ".jpg");
} else {
mediaApiFactory.makeRequestStartVideoPartialUpload(file.getName(), fileContent.length).start(null, initialResultListener);
pictureProgressText.setText("Uploading " + currentMedia.getName() + ".mp4");
}
然后我使用retrofit将视频/图像发送到服务器
然后我处理响应
if (result != null && result.isSuccess()) {
PartialUploadInitialDTO dto = result.getData();
currentUrlSuffix = dto.urlSuffix;
currentMinBytes = 0;
currentMaxBytes = START_BYTES_MAX;
chunks = new ArrayList<>();
chunks.add(Arrays.copyOfRange(fileContent, (int)currentMinBytes, (int)currentMaxBytes));
if (currentMedia.getType() == IMAGE) {
mediaApiFactory.makeRequestContinueImagePartialUpload(currentUrlSuffix, chunks.get(chunks.size() - 1)).start(null, intermediateResultListener);
} else {
mediaApiFactory.makeRequestContinueVideoPartialUpload(currentUrlSuffix, chunks.get(chunks.size() - 1)).start(null, intermediateResultListener);
}
}
然后继续上传，直到读取完总字节数(成功状态)
if (result != null && result.isSuccess()) {
if (result.getData() instanceof PartialUploadInProgressDTO) { //contains the success status of a complete dto as well (me being lazy)
PartialUploadInProgressDTO dto = (PartialUploadInProgressDTO)result.getData();
if (dto.success != null && dto.success) { //denotes that the upload was successful
currentFile++;
if (currentMedia.isDeleted()) {
if (currentMedia.getPath() != null) {
MediaUtils.deleteFile(currentMedia.getPath());
}
}
if (mediaInvocationListener != null) {
mediaInvocationListener.onUpdateProgress(currentFile, count);
}
pictureProgressBar.setProgress(100);
next();
} else { //the upload is still in progress
currentMinBytes = dto.nextExpectedMin;
currentMaxBytes = dto.nextExpectedMax;
chunks.add(Arrays.copyOfRange(fileContent, (int) currentMinBytes, (int) currentMaxBytes)); //adds the next chunk of bytes
int progress = (int)((float)currentMinBytes / fileContent.length * 100);
pictureProgressBar.setProgress(progress);
if (currentMedia.getType() == IMAGE) {
mediaApiFactory.makeRequestContinueImagePartialUpload(currentUrlSuffix, chunks.get(chunks.size() - 1)).start(null, intermediateResultListener); //recursive to this method
} else {
mediaApiFactory.makeRequestContinueVideoPartialUpload(currentUrlSuffix, chunks.get(chunks.size() - 1)).start(null, intermediateResultListener); //recursive to this method
}
}
}
}
这是到达服务器之前和之后的平均原子树 之前(但在 QTQuick 运行之后):
ftyp (24 bytes)
moov (15372 bytes)
mdat (67290713 bytes)
之后( block 成功上传)
REM This is available upon request looks something like
ftyp (bytes)
moov (bytes)
NOTMDAT(bytes)
无论如何，对于冗长的帖子感到抱歉。如果需要其他任何内容，请询问，我会对此进行编辑。
最佳答案
所以我发现问题是代码中的错误。当字节具有其起始值和终止值时，您无需考虑写入的最后一个字节，只需继续使用相同的数字即可。所以以下是正确的:
dto.nextExpectedMin = upload.getCurrentBytesMax();
dto.nextExpectedMax = upload.getCurrentBytesMax() + (upload.getCurrentBytesMax() - upload.getCurrentBytesMin());
无论我在哪里
dto.nextExpectedMin = upload.getCurrentBytesMax() + 1;
dto.nextExpectedMax = upload.getCurrentBytesMax() + (upload.getCurrentBytesMax() - upload.getCurrentBytesMin());
之前
关于java - 用 Java 构建了部分上传系统，但视频损坏，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/59979215/