azoozs
commented
7 months ago I’ve discovered that the issue isn’t linked to bufferingGoal. Instead, it’s due to minor gaps between periods. I believe this occurs because MP4Box sets the duration of each period based on the audio stream’s duration, not the video stream’s. You can verify the duration of the video stream using ffprobe:
import subprocess
import json
import datetime
command = f"ffprobe -v quiet -print_format json -show_format -show_streams input_001.mp4"
# Execute the command and get the output
process = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True)
out, err = process.communicate()
# Convert the output to a Python dictionary
output_dict = json.loads(out)
# Extract the video stream duration
for stream in output_dict['streams']:
if stream['codec_type'] == 'video':
video_duration = stream['duration']
print(f"Video Duration: {video_duration}")
if stream['codec_type'] == 'audio':
audio_duration = stream['duration']
print(f"Audio Duration: {audio_duration}")
Afterwards, you’ll need to manually adjust the duration of each period. This should resolve the issue.
Dynamic Solution
from decimal import Decimal
from bs4 import BeautifulSoup
import subprocess
import json
import os
import glob
class PrecisePeriodMPDProducer():
input_filename = None
output_mpd_filename = None
filename_without_extension = None
def __init__(self, input_filename, output_mpd_filename):
self.input_filename = input_filename
self.output_mpd_filename = output_mpd_filename
self.filename_without_extension = os.path.splitext(self.input_filename)[0]
def split_video(self, duration=10):
_, extension = os.path.splitext(self.input_filename)
if extension.lower() != '.mp4':
print(f"The file {self.input_filename} is not an .mp4 file.")
return
command = f"ffmpeg -i {self.input_filename} -c copy -map 0 -segment_time {duration} -f segment {self.filename_without_extension}_%03d.mp4"
process = subprocess.Popen(command, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=True)
out, err = process.communicate()
if process.returncode != 0:
print( f"The split_video command failed with return code: {process.returncode}")
def get_target_files(self):
return [f for f in glob.glob("*.mp4") if '_dashinit' not in f and f != self.input_filename]
def generate_mpd_file(self, dash_duration=10000):
files_list = self.get_target_files()
command = "MP4Box" + f" -dash {dash_duration}"
for i, file in enumerate(files_list):
command += f" {file}:period={i}"
command += f" -out {self.output_mpd_filename}"
process = subprocess.Popen(command, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL, shell=True)
out, err = process.communicate()
if process.returncode != 0:
print( f"The generate_mpd_file command failed with return code: {process.returncode}")
print("The command was used to create an MPD file: \n" + command )
def convert_seconds_to_mpd_format(self, seconds):
minutes, seconds = divmod(Decimal(seconds), 60)
hours, minutes = divmod(minutes, 60)
mpd_duration = "PT{}H{}M{}S".format(int(hours), int(minutes), seconds)
return mpd_duration
def get_video_duration(self, filename):
command = f"ffprobe -v quiet -print_format json -show_format -show_streams {filename}"
process = subprocess.Popen(command, stdout=subprocess.PIPE, shell=True)
out, err = process.communicate()
output_dict = json.loads(out)
return Decimal(output_dict['streams'][0]['duration'])
def execute(self):
self.split_video(duration=10)
self.generate_mpd_file(dash_duration=10000)
with open(f'./{self.output_mpd_filename}', 'r') as mpd_file:
mpd_data = mpd_file.read()
soup = BeautifulSoup(mpd_data, 'xml')
periods = soup.find_all('Period')
total_video_duration = 0
for i, period in enumerate(periods):
base_url = period.find('BaseURL')
file_path = os.path.abspath(str(base_url.text).replace("_dashinit",""))
video_duration = self.get_video_duration(file_path)
total_video_duration += video_duration
#print("\n\n" + period.get('duration') + " actual duration: " + str(video_duration) + "\n")
period['duration'] = self.convert_seconds_to_mpd_format(video_duration) # seconds in ISO 8601 duration format
#print("Total video duration: " + str(total_video_duration))
mpd_file.close()
#print("Total video duration in MPD Format: " + self.convert_seconds_to_mpd_format(total_video_duration))
with open(f'./{self.output_mpd_filename}', 'w') as mpd_file:
mpd_file.write(str(soup))
if __name__ == '__main__':
precise_period_mpd_producer = PrecisePeriodMPDProducer("input.mp4","out.mpd")
precise_period_mpd_producer.execute()
Have you read the Tutorials? Yes
Have you read the FAQ and checked for duplicate open issues? Yes
If the question is related to FairPlay, have you read the tutorial?
N/A
What version of Shaka Player are you using? v4.7.11 and I also tested v2.5.6
What browser and OS are you using? Windows 10 x64 \ Chrome
Please ask your question
I'm using the Shaka Player to play a multi-period MPEG-DASH video, but I'm encountering an issue with the buffering goal. I have an
input.mp4file with a duration of 30 seconds, and I want to split it into segments of 10 seconds each.Here are the steps I followed:
Step 1: I used ffmpeg to split the video into segments:
This resulted in the following output files:
Step 2: I used MP4Box to dash the segments into periods:
This resulted in the following output files:
out.mpdI then attempted to play the
out.mpdfile using the Shaka Player in my HTML file. The player is configured with arebufferingGoalandbufferingGoalof 10. However, the buffering goal does not seem to work with the multi-period MPEG-DASH video.HTML file:
When I use the
https://storage.googleapis.com/shaka-demo-assets/angel-one/dash.mpdURL, it works fine. But when I use my ownhttps://raw.githubusercontent.com/azoozs/shaka-player-multi-period/main/videos/out.mpdURL, the buffering goal doesn't seem to work.My question is: Why doesn't the
bufferingGoal: 10setting work with a multi-period MPEG-DASH video? My aim is to preload the subsequent period before the current one ends, ensuring a seamless transition between periods. Any help would be greatly appreciated. Thank you.