poc

1 files changed, 117 insertions, 0 deletions

diff --git a/mediabrowser/ffmpeg.py b/mediabrowser/ffmpeg.py
new file mode 100644
index 0000000..ba4ee28
--- /dev/null
+++ b/mediabrowser/ffmpeg.py
@@ -0,0 +1,117 @@
+import json
+import re
+import codecs
+import logging
+from subprocess import Popen, PIPE, DEVNULL
+import shlex
+
+utf8reader = codecs.getreader('utf-8')
+
+
+def LoggedPopen(command, *args, **kwargs):
+    logging.info("Popen(command={} args={}) with kwargs={}".format(
+        " ".join(map(repr, command)),
+        " ".join(map(repr, args)),
+        " ".join(map(repr, kwargs))))
+    return Popen(command, *args, **kwargs)
+
+
+def ffprobe_data(ospath):
+    logging.info('ffprobe %s', ospath)
+    process = LoggedPopen(['ffprobe', '-v', 'quiet', '-print_format', 'json',
+                           '-show_format', '-show_streams', ospath], stdout=PIPE, stderr=DEVNULL)
+    data = json.load(utf8reader(process.stdout))
+    assert process.wait() == 0, "ffprobe failed"
+    process.stdout.close()
+    return data
+
+
+def stream(ospath, ss, t):
+    logging.info('start ffmpeg stream h264 480p on path=%s ss=%s t=%s', ospath, ss, t)
+    t_2 = t + 2.0
+    cutter = LoggedPopen(
+        shlex.split("ffmpeg -ss {ss:.6f} -async 1 -i ".format(**locals())) +
+        [ospath] +
+        shlex.split("-c:a aac -strict experimental -ac 2 -b:a 44k"
+                    ""
+                    " -c:v libx264 -pix_fmt yuv420p -profile:v high -level 4.0 -preset ultrafast -trellis 0"
+                    " -crf 31 -vf scale=w=trunc(oh*a/2)*2:h=360"
+                    ""
+                    " -f mpegts -output_ts_offset {ss:.6f} -t {t:.6f} pipe:%d.ts".format(**locals())),
+        stdout=PIPE, stderr=DEVNULL)
+    return cutter
+
+
+def find_next_keyframe(ospath, start, max_offset):
+    """
+    :param: start: start search pts as float '123.123'
+    :param: max_offset: max offset after start as float
+    :return: PTS of next iframe but not search longer than max_offset
+    """
+    logging.info("start ffprobe to find next i-frame from {}".format(start))
+    if start == 0.0:
+        return 0.0
+    process = LoggedPopen(
+        shlex.split("ffprobe -read_intervals {start:.6f}%+{max_offset:.6f} -show_frames "
+                    "-select_streams v -print_format flat".format(**locals())) + [ospath],
+        stdout=PIPE, stderr=DEVNULL)
+    data = {'frame': None}
+    try:
+        line = process.stdout.readline()
+        while line:
+            frame, name, value = re.match('frames\\.frame\\.(\d+)\\.([^=]*)=(.*)', line.decode('ascii')).groups()
+            if data['frame'] != frame:
+                data.clear()
+                data['frame'] = frame
+
+            data[name] = value
+            if 'key_frame' in data and data['key_frame'] == '1':
+                if 'pkt_pts_time' in data and data['pkt_pts_time'][1:-1] != 'N/A' and float(
+                        data['pkt_pts_time'][1:-1]) > start:
+                    logging.info("Found pkt_pts_time={}".format(data['pkt_pts_time']))
+                    return float(data['pkt_pts_time'][1:-1])
+                elif 'pkt_dts_time' in data and data['pkt_dts_time'][1:-1] != 'N/A' and float(
+                        data['pkt_dts_time'][1:-1]) > start:
+                    logging.info("Found pkt_dts_time={}".format(data['pkt_dts_time']))
+                    return float(data['pkt_dts_time'][1:-1])
+
+            line = process.stdout.readline()
+        raise Exception("Failed to find next i-frame in {} .. {} of {}".format(start, max_offset, ospath))
+    finally:
+        process.stdout.close()
+        process.terminate()
+        logging.info("finished ffprobe to find next i-frame from {}".format(start))
+
+
+def calculate_splittimes(ospath, chunk_duration):
+    """
+    :param ospath: path to media file
+    :return: list of PTS times to split the media, in the form of
+                    ((start1, duration1),  (start2, duration2), ...)
+                    (('24.949000', '19.500000'),  ('44.449000', ...), ...)
+            Note: - start2 is equal to start1 + duration1
+                  - sum(durationX) is equal to media duration
+    """
+
+    def calculate_points(media_duration):
+        pos = 10
+        while pos < media_duration:
+            yield pos
+            pos += chunk_duration
+
+    duration = float(ffprobe_data(ospath)['format']['duration'])
+    points = list(calculate_points(duration))
+    adj_points = points
+    # for point in points:
+    #     adj_points += [find_next_iframe(ospath, point, chunk_duration / 2.0)]
+    #
+    for (point, nextPoint) in zip([0.0] + adj_points, adj_points + [duration]):
+        yield ("{:0.6f}".format(point), "{:0.6f}".format(nextPoint - point))
+
+
+def thumbnail_png(path, size):
+    logging.debug("thumbnail %s", path)
+    process = LoggedPopen(['ffmpegthumbnailer', '-i', path,
+                           '-o', '-', '-s', str(size), '-c', 'png'],
+                          stdout=PIPE, stderr=DEVNULL)
+    return process