Sound pops & clicks when playing HLS stream by using Safari native playback

[emmitrin]

System info

Operating System: macOS Ventura 13.2 Shaka Packager Version: packager-osx-x64 version v2.6.1-634af65-release

Issue and steps to reproduce the problem

I have the following input files:

• video.mp4 – h264 video w\ sound or subtitle streams
• audio0.m4a – first voice actor
• audio1.m4a – second voice actor

I'm trying to make a HLS stream containing the video and two audio tracks:

Packager Command:

packager \
'in=video.mp4,stream=video,segment_template=720p/$Number$.ts,playlist_name=720p.m3u8,iframe_playlist_name=720p_iframe.m3u8' \
'in=audio0.m4a,stream=audio,segment_template=audio0/$Number$.ts,playlist_name=audio0/main.m3u8,hls_group_id=audio,hls_name=First_actor' \ 
'in=audio1.m4a,stream=audio,segment_template=audio1/$Number$.ts,playlist_name=audio1/main.m3u8,hls_group_id=audio,hls_name=Second_actor' \ 
--hls_master_playlist_output 720p_master.m3u8

The resulting stream is playing fine in hls.js-powered players, but I can constantly hear choppy clicking sound when trying to play the stream via Safari's native HLS playback.

When I switch the segment_template file extension for audio streams to .aac, everything is fine for both Safari and hls.js.

But I'm locked to MPEG-2 container for audio streams because I also need raw SAMPLE-AES encryption which is supported only for MPEG-2 TS in Hls.js.

Is this happening due to ID3 com.apple.streaming.transportStreamTimestamp tag getting lost when the audio is stored in .ts segments separated from the video?

Is there anything related to Shaka packager that may fix this issue?

[emmitrin]

ffprobe for input audio file

```json { "streams": [ { "index": 0, "codec_name": "aac", "codec_long_name": "AAC (Advanced Audio Coding)", "profile": "LC", "codec_type": "audio", "codec_tag_string": "mp4a", "codec_tag": "0x6134706d", "sample_fmt": "fltp", "sample_rate": "48000", "channels": 2, "channel_layout": "stereo", "bits_per_sample": 0, "id": "0x1", "r_frame_rate": "0/0", "avg_frame_rate": "0/0", "time_base": "1/48000", "start_pts": 0, "start_time": "0.000000", "duration_ts": 70435824, "duration": "1467.413000", "bit_rate": "130085", "nb_frames": "68786", "extradata_size": 5, "disposition": { "default": 1, "dub": 0, "original": 0, "comment": 0, "lyrics": 0, "karaoke": 0, "forced": 0, "hearing_impaired": 0, "visual_impaired": 0, "clean_effects": 0, "attached_pic": 0, "timed_thumbnails": 0, "captions": 0, "descriptions": 0, "metadata": 0, "dependent": 0, "still_image": 0 }, "tags": { "language": "eng", "handler_name": "SoundHandler", "vendor_id": "[0][0][0][0]" } } ], "format": { "filename": "audio0.m4a", "nb_streams": 1, "nb_programs": 0, "format_name": "mov,mp4,m4a,3gp,3g2,mj2", "format_long_name": "QuickTime / MOV", "start_time": "0.000000", "duration": "1467.413000", "size": "24677419", "bit_rate": "134535", "probe_score": 100, "tags": { "major_brand": "M4A ", "minor_version": "512", "compatible_brands": "M4A isomiso2", "title": "testvideo", "encoder": "Lavf59.27.100" } } } ```