pyav: saving video and audio to separate files from streaming hls

Question

I am writing a script to extract the video keyframes (to frame_{0}.jpg ) and audio to the a separate .mp3 file. Here is what I have so far:

import os
import av

path_to_video = 'http://184.72.239.149/vod/smil:BigBuckBunny.smil/playlist.m3u8'
container = av.open(path_to_video)

stream = container.streams.video[0]
audio_stream = container.streams.audio[0]

stream.codec_context.skip_frame = 'NONKEY'
tgt_path = "./frames"
if not os.path.isdir(tgt_path):
    os.makedirs(tgt_path)
for frame in container.decode(stream):
   tgt_filename = os.path.join(tgt_path,'frame-{:09d}.jpg'.format(frame.pts))
   frame.to_image().save(tgt_filename,quality=80)

How do I save the audio stream to a file (preferably in chunks). Do i need to launch a separate capture routine and run in parallel, or can I capture in above loop?

I have looked over the pyav github posts to no luck, unfortunately. Not sure how I can do this in a single loop.

Answer 1

This is from an answer posted on pyav github repo:

import av

input_container = av.open(
    'http://184.72.239.149/vod/smil:BigBuckBunny.smil/playlist.m3u8')
input_stream = input_container.streams.get(audio=0)[0]

output_container = av.open('live_stream.mp3', 'w')
output_stream = output_container.add_stream('mp3')

for frame in input_container.decode(input_stream):
    frame.pts = None
    for packet in output_stream.encode(frame):
        output_container.mux(packet)

for packet in output_stream.encode(None):
    output_container.mux(packet)

output_container.close()