http - Serving video files from Tornado -

i have few hundred video files on server. since i'm not big business, find difficult transcode , maintain copies in storage available me. setup involves nginx , tornado.

to solve problem, decided try , transcode on fly , serve these temporary files on-demand.

before attempted create subprocess try , convert files me, decided try , serve static video file via tornado.

class mediahandler(tornado.web.requesthandler):     def serve(self, media, max_bufsize=1*1024*1024):          bytes_read = 0         file_length = none         remaining = none          self.set_header('content-type', 'video/mp4')         open(media.name, 'rb') f:             while 1:                 # while transcoding, file size changing                 # compute every time                 file_length = os.fstat(f.fileno()).st_size  # current length                 remaining = file_length - bytes_read    # compute remaining bytes                  # we're producing faster we're consuming...                 if remaining == 0:                     break                  buffer_size = max_bufsize if max_bufsize < remaining else remaining                 bytes = f.read(buffer_size)                 assert len(bytes) == buffer_size                 bytes_read += buffer_size                  self.write(bytes)                 self.flush()       def get(self):         log('media request: %s' % (self.request.uri))         #xxx: hard-coded in sense..fix         media_path = os.path.abspath(os.path.join(dir_path, self.request.uri[1:]))  #strip leading '/'         log('media_path: %s' % (media_path))         try:             media = avprobe(media_path)         except subprocessexception, e:             raise e          if media.video_codec not in valid_video_codecs or \                 media.audio_codec not in valid_audio_codecs:             # transcode , serve             pass         else:             self.serve(media)         self.finish() 

i noticed when tried serve file tornado, firefox not load video @ all. upon checking, response headers follows:

http/1.1 200 ok date: thu, 02 jul 2015 00:04:50 gmt content-type: video/mp4 transfer-encoding: chunked connection: keep-alive server: tornadoserver/4.2 

nginx seems generate following headers when ask serve same file:

http/1.1 206 partial content server: nginx/1.8.0 date: wed, 01 jul 2015 23:57:06 gmt content-type: video/mp4 content-length: 65796881 last-modified: thu, 09 apr 2015 21:47:56 gmt connection: keep-alive etag: "5526f38c-3ebfb11" content-range: bytes 0-65796880/65796881 

it seems firefox doesn't data i'm sending it. spits out following on console:

media resource http://xxxx:8000/video_test/media/test.mp4 not decoded. candidate resources failed load. media load paused. 

could point out i'm doing incorrectly , how serve static media tornado (without using staticfilehandler..since don't think can use ultimate purpose).

also, there better way achieve on-the-fly transcoding+streaming?

browsers don't download whole file embedded video; want able issue http range requests download partial chunks (to support seeking, etc). browsers strict , refuse load video @ if doesn't have correct content-range header. unfortunately makes difficult serve video when file size not known in advance.

if files small enough can transcode whole thing temporary file before serving it, can , serve content-range in same way staticfilehandler does. if not, think may need use more complex protocol such hls or mpeg-dash make work browsers.