Question

我已经被困了几个星期，试图使用ffmpeg将用户上传的视频转换为flv。我使用heroku来托管我的网站，并使用s3boto将我的静态和媒体文件存储在amazon S3上。初始视频文件将正常上传，但是当我检索视频并运行芹菜任务时（在上载初始视频文件的同一视图中），新文件将不会存储在S3上。我一直试图让这个工作超过一个月，没有运气，并且没有很好的资源可用于学习如何做到这一点，所以我想也许我可以在存储视频之前运行ffmpeg任务我也许能够让它发挥作用。不幸的是，我仍然不是一个非常先进的python（或django），所以我甚至不知道这是否可行。有人有主意吗？我愿意在这一点上使用任何解决方案，无论多么难看，只要它成功进行视频上传并使用ffmpeg转换为flv，结果文件存储在S3上。我的情况似乎并不常见，因为无论我在哪里，我找不到解释我应该尝试做什么的解决方案。因此，我将非常感谢任何指导。谢谢。我的相关代码如下：

#models.py
def content_file_name(instance, filename):
    ext = filename.split('.')[-1]
    new_file_name = "remove%s.%s" % (uuid.uuid4(), ext)
    return '/'.join(['videos', instance.teacher.username, new_file_name])

class BroadcastUpload(models.Model):
    title = models.CharField(max_length=50, verbose_name=_('Title'))
    description = models.TextField(max_length=100, verbose_name=_('Description'))
    teacher = models.ForeignKey(User, null=True, blank=True, related_name='teacher')
    created_date = models.DateTimeField(auto_now_add=True)
    video_upload = models.FileField(upload_to=content_file_name)
    flvfilename = models.CharField(max_length=100, null=True, blank=True)
    videothumbnail = models.CharField(max_length=100, null=True, blank=True)

#tasks.py
@task(name='celeryfiles.tasks.convert_flv')
def convert_flv(video_id):
    video = BroadcastUpload.objects.get(pk=video_id)
    print "ID: %s" % video.id
    id = video.id
    print "VIDEO NAME: %s" % video.video_upload.name
    teacher = video.teacher
    print "TEACHER: %s" % teacher
    filename = video.video_upload
    sourcefile = "%s%s" % (settings.MEDIA_URL, filename)
    vidfilename = "%s_%s.flv" % (teacher, video.id)
    targetfile = "%svideos/flv/%s" % (settings.MEDIA_URL, vidfilename)
    ffmpeg = "ffmpeg -i %s %s" % (sourcefile, vidfilename)
    try:
        ffmpegresult = subprocess.call(ffmpeg)
        #also tried separately with following line:
        #ffmpegresult = commands.getoutput(ffmpeg)
        print "---------------FFMPEG---------------"
        print "FFMPEGRESULT: %s" % ffmpegresult
    except Exception as e:
        ffmpegresult = None
        print("Failed to convert video file %s to %s" % (sourcefile, targetfile))
        print(traceback.format_exc())
    video.flvfilename = vidfilename
    video.save()

@task(name='celeryfiles.tasks.ffmpeg_image')        
def ffmpeg_image(video_id):
    video = BroadcastUpload.objects.get(pk=video_id)
    print "ID: %s" %video.id
    id = video.id
    print "VIDEO NAME: %s" % video.video_upload.name
    teacher = video.teacher
    print "TEACHER: %s" % teacher
    filename = video.video_upload
    sourcefile = "%s%s" % (settings.MEDIA_URL, filename)
    imagefilename = "%s_%s.png" % (teacher, video.id)
    thumbnailfilename = "%svideos/flv/%s" % (settings.MEDIA_URL, thumbnailfilename)
    grabimage = "ffmpeg -y -i %s -vframes 1 -ss 00:00:02 -an -vcodec png -f rawvideo -s 320x240 %s" % (sourcefile, thumbnailfilename)
    try:        
         videothumbnail = subprocess.call(grabimage)
         #also tried separately following line:
         #videothumbnail = commands.getoutput(grabimage)
         print "---------------IMAGE---------------"
         print "VIDEOTHUMBNAIL: %s" % videothumbnail
    except Exception as e:
         videothumbnail = None
         print("Failed to convert video file %s to %s" % (sourcefile, thumbnailfilename))
         print(traceback.format_exc())
    video.videothumbnail = imagefilename
    video.save()

#views.py
def upload_broadcast(request):
    if request.method == 'POST':
        form = BroadcastUploadForm(request.POST, request.FILES)
        if form.is_valid():
            upload=form.save()
            video_id = upload.id
            image_grab = ffmpeg_image.delay(video_id)
            video_conversion = convert_flv.delay(video_id)
            return HttpResponseRedirect('/current_classes/')
    else:
        form = BroadcastUploadForm(initial={'teacher': request.user,})
    return render_to_response('videos/create_video.html', {'form': form,}, context_instance=RequestContext(request))

#settings.py
DEFAULT_FILE_STORAGE = 'myapp.s3utils.MediaRootS3BotoStorage'
DEFAULT_S3_PATH = "media"
STATICFILES_STORAGE = 'myapp.s3utils.StaticRootS3BotoStorage'
STATIC_S3_PATH = "static"
AWS_STORAGE_BUCKET_NAME = 'my_bucket'
CLOUDFRONT_DOMAIN = 'domain.cloudfront.net'
AWS_ACCESS_KEY_ID = 'MY_KEY_ID'
AWS_SECRET_ACCESS_KEY = 'MY_SECRET_KEY'
MEDIA_ROOT = '/%s/' % DEFAULT_S3_PATH
MEDIA_URL = 'http://%s/%s/' % (CLOUDFRONT_DOMAIN, DEFAULT_S3_PATH)
...

#s3utils.py
from storages.backends.s3boto import S3BotoStorage
from django.utils.functional import SimpleLazyObject

StaticRootS3BotoStorage = lambda: S3BotoStorage(location='static')
MediaRootS3BotoStorage  = lambda: S3BotoStorage(location='media')

如果需要，我可以添加任何其他信息来帮助我解决问题。

Answer 1

不确定您是否从涉及上传到云（parse.com）的媒体文件的类似云场景获得帮助，这些场景需要在到达时使用ffmpeg进程并将输出（.mp4）写回到Cloud（通过Curl解析）。 / p>

请参阅当前在Heroku WEB进程中运行的paste shellscript，该进程可以使用CLI调用脚本。

如果你可以对它进行调整，那么shellcript会在某个进程中运行，该进程具有对输入的http访问权限，以及可以写入临时文件的文件系统，如果你可以将tmp FS中的ffmpeg.output从CURL -X POST回到S3，那么它可能对你有用。

Answer 2

嘿，你犯了一个简单的错误

而不是使用settings.Media_url使用media_root

Answer 3

为了将subprocess.call与包含所有参数的字符串一起使用，您需要添加shell=True：

ffmpegresult = subprocess.call(ffmpeg, shell=True)
...
videothumbnail = subprocess.call(grabimage, shell=True)

Answer 4

我已对您的代码进行了一些修改，现在它正在运行。一些问题：

我已将任务调用放在模型的save方法中。如果你愿意，你可以把它放在视图中。正如你所做的那样。
我的解决方案是转码为临时文件，然后上传它到AWS S3。

以下是代码：

from django.contrib.auth.models import User

def content_file_name(instance, filename):
    ext = filename.split('.')[-1]
    new_file_name = "remove%s.%s" % (uuid.uuid4(), ext)
    return '/'.join(['videos', instance.teacher.username, new_file_name])

class BroadcastUpload(models.Model):
    title = models.CharField(max_length=50, verbose_name=_('Title'))
    description = models.TextField(max_length=100, verbose_name=_('Description'))
    teacher = models.ForeignKey(User, null=True, blank=True, related_name='teacher')
    created_date = models.DateTimeField(auto_now_add=True)
    video_upload = models.FileField(upload_to=content_file_name)
    #flvfilename = models.CharField(max_length=100, null=True, blank=True)
    video_flv = models.FileField(upload_to='flv', blank=True)
    #videothumbnail = models.CharField(max_length=100, null=True, blank=True)
    video_thumbnail = models.FileField(upload_to='thumbs', blank=True)

    def __unicode__(self):
        return u'%s - %s' % (self.title, self.teacher)

    def save(self, *args, **kwargs):
        # optional parameter to indicate whether perform
        # conversion or not. Defaults to True
        do_conversion = kwargs.pop('do_conversion', True)

        # do something only when the entry is created
        if not self.pk:
            super(BroadcastUpload, self).save(*args, **kwargs)

        # do something every time the entry is updated
        if do_conversion:
            ffmpeg_image.delay(self.pk)
            convert_flv.delay(self.pk)

        # then call the parent save:
        super(BroadcastUpload, self).save(*args, **kwargs)

from django.core.files.uploadedfile import SimpleUploadedFile
import tempfile

@task
def convert_flv(video_id):
    video = BroadcastUpload.objects.get(pk=video_id)
    print "ID: %s" % video.id
    id = video.id
    print "VIDEO NAME: %s" % video.video_upload.name
    teacher = video.teacher
    print "TEACHER: %s" % teacher
    filename = video.video_upload
    #sourcefile = "%s%s" % (settings.MEDIA_URL, filename)
    sourcefile = video.video_upload.url
    # ffmpeg cannot deal with https?
    sourcefile = sourcefile.replace("https","http")
    print "sourcefile: %s" % sourcefile

    # temporary output image
    OUTPUT_VIDEO_EXT = 'flv'
    OUTPUT_VIDEO_CONTENT_TYPE = 'video/flv'    
    f_out = tempfile.NamedTemporaryFile(suffix=".%s"%OUTPUT_VIDEO_EXT, delete=False)
    tmp_output_video = f_out.name

    #ffmpeg = "ffmpeg -i '%s' -qscale 0 -ar 44100 '%s'" % (sourcefile, vidfilename)
    ffmpeg = "ffmpeg -y -i '%s' -qscale 0 -ar 44100 '%s'" % (sourcefile, tmp_output_video)
    print "convert_flv: %s" % ffmpeg
    try:
        ffmpegresult = subprocess.call(ffmpeg, shell=True)
        #also tried separately with following line:
        #ffmpegresult = commands.getoutput(ffmpeg)
        print "---------------FFMPEG---------------"
        print "FFMPEGRESULT: %s" % ffmpegresult
    except Exception as e:
        ffmpegresult = None
        #print("Failed to convert video file %s to %s" % (sourcefile, targetfile))
        print("Failed to convert video file %s to %s" % (sourcefile, tmp_output_video))
        #print(traceback.format_exc())
        print "Error: %s" % e

    #vidfilename = "%s_%s.flv" % (teacher, video.id)
    vidfilename = "%s_%s.%s" % (teacher, video.id, OUTPUT_VIDEO_EXT)
    #targetfile = "%svideos/flv/%s" % (settings.MEDIA_URL, vidfilename)

    # prepare an object with the generated temporary image
    suf = SimpleUploadedFile( 
                             vidfilename,
                             f_out.read(),
                             content_type=OUTPUT_VIDEO_CONTENT_TYPE
                             )

    # upload converted video to S3 and set the name.
    # save set to False to avoid infinite loop
    video.video_flv.save(
                                vidfilename,
                                suf,
                                save=False 
                                )

    # delete temporary output file
    print "[convert_flv] removing temporary file: %s" % tmp_output_video
    os.remove(tmp_output_video)

    #video.flvfilename = vidfilename

    # add do_conversion=False to avoid infinite loop.
    # update_fields is needed in order to not delete video_thumbnail
    # if it did not exist when starting the task
    video.save(do_conversion=False, update_fields=['video_flv'])

@task       
def ffmpeg_image(video_id):
    video = BroadcastUpload.objects.get(pk=video_id)
    print "ID: %s" %video.id
    id = video.id
    print "VIDEO NAME: %s" % video.video_upload.name
    teacher = video.teacher
    print "TEACHER: %s" % teacher
    filename = video.video_upload
    #sourcefile = "%s%s" % (settings.MEDIA_URL, filename)
    sourcefile = video.video_upload.url
    # ffmpeg cannot deal with https?
    sourcefile = sourcefile.replace("https","http")

    # temporary output image
    OUTPUT_IMAGE_EXT = 'png'
    OUTPUT_IMAGE_CONTENT_TYPE = 'image/png'    
    f_out = tempfile.NamedTemporaryFile(suffix=".%s"%OUTPUT_IMAGE_EXT, delete=False)
    tmp_output_image = f_out.name

    #grabimage = "ffmpeg -y -i '%s' -vframes 1 -ss 00:00:02 -an -vcodec png -f rawvideo -s 320x240 '%s'" % (sourcefile, thumbnailfilename)
    grabimage = "ffmpeg -y -i '%s' -vframes 1 -ss 00:00:02 -an -vcodec png -f rawvideo -s 320x240 '%s'" % (sourcefile, tmp_output_image)
    print "ffmpeg_image: %s" % grabimage
    try:        
         videothumbnail = subprocess.call(grabimage, shell=True)
         #also tried separately following line:
         #videothumbnail = commands.getoutput(grabimage)
         print "---------------IMAGE---------------"
         print "VIDEOTHUMBNAIL: %s" % videothumbnail
    except Exception as e:
         videothumbnail = None
         #print("Failed to extract thumbnail from %s to %s" % (sourcefile, thumbnailfilename))
         print("Failed to extract thumbnail from %s to %s" % (sourcefile, tmp_output_image))
         #print(traceback.format_exc())
         print "Error: %s" % e

    #imagefilename = "%s_%s.png" % (teacher, video.id)
    imagefilename = "%s_%s.%s" % (teacher, video.id, OUTPUT_IMAGE_EXT)
    #thumbnailfilename = "%svideos/flv/%s" % (settings.MEDIA_URL, thumbnailfilename)
    #thumbnailfilename = 'thumbnail_image.png'

    # prepare an object with the generated temporary image
    suf = SimpleUploadedFile( 
                             imagefilename,
                             f_out.read(),
                             content_type=OUTPUT_IMAGE_CONTENT_TYPE
                             )

    # upload converted image to S3 and set the name.
    # save set to False to avoid infinite loop

    video.video_thumbnail.save(
                                imagefilename,
                                suf,
                                save=False 
                                )

    # delete temporary output file
    print "[ffmpeg_image] removing temporary file: %s" % tmp_output_image
    os.remove(tmp_output_image)

    #video.videothumbnail = imagefilename

    # add do_conversion=False to avoid infinite loop
    video.save(do_conversion=False, update_fields=['video_thumbnail'])

在存储视频之前，我可以使用ffmpeg从表单转换django视频上传吗？

4 个答案: