<html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body bgcolor="#FFFFFF" text="#000000"> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <pre style="white-space: pre-wrap; color: rgb(0, 0, 0); font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Dear PulseAudio folks, We are using PulseAudio in our automotive project, the progress is pretty good so far. I need some help for solving the sync problems between two speakers. </pre> The pic below is the data flow of the two speakers: <img src="cid:part1.08010808.01020401@gmail.com" alt=""> below is the pactl list modules information : uid=0 gid=0@nutshell:/ # pactl list sinks Using shared memory pool with 1024 slots of size 64.0 KiB each, total size is 64.0 MiB, maximum usable slot size is 65496 Trying to connect to /tmp/pulse/native... SHM possible: yes Protocol version: remote 30, local 30 Negotiated SHM: yes Sink #0 State: RUNNING Name: audioio.5 Description: (null) Driver: module-audioio-sink.c Sample Specification: s16le 2ch 48000Hz Channel Map: front-left,front-right Owner Module: 3 Mute: no Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB balance 0.00 Base Volume: 65536 / 100% / 0.00 dB Monitor Source: audioio.5.monitor Latency: 0 usec, configured 128000 usec Flags: HARDWARE DECIBEL_VOLUME LATENCY Properties: device.icon_name = "audio-card" Formats: pcm Sink #4 State: RUNNING Name: audioio.0 Description: (null) Driver: module-audioio-sink.c Sample Specification: s16le 2ch 48000Hz Channel Map: front-left,front-right Owner Module: 8 Mute: no Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB balance 0.00 Base Volume: 65536 / 100% / 0.00 dB Monitor Source: audioio.0.monitor Latency: 0 usec, configured 128000 usec Flags: HARDWARE DECIBEL_VOLUME LATENCY Properties: device.icon_name = "audio-card" Formats: pcm Sink #5 State: RUNNING Name: audioio.1 Description: (null) Driver: module-audioio-sink.c Sample Specification: s16le 2ch 48000Hz Channel Map: front-left,front-right Owner Module: 9 Mute: no Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB balance 0.00 Base Volume: 65536 / 100% / 0.00 dB Monitor Source: audioio.1.monitor Latency: 228454 usec, configured 250000 usec Flags: HARDWARE DECIBEL_VOLUME LATENCY Properties: device.icon_name = "audio-card" Formats: pcm Sink #6 State: RUNNING Name: audioio.6 Description: audioio.0, audioio.1 Driver: module-iauto-combine-sink.c Sample Specification: s16le 2ch 48000Hz Channel Map: front-left,front-right Owner Module: 7 Mute: no Volume: front-left: 65536 / 100% / 0.00 dB, front-right: 65536 / 100% / 0.00 dB balance 0.00 Base Volume: 65536 / 100% / 0.00 dB Monitor Source: audioio.6.monitor Latency: 130235 usec, configured 250000 usec Flags: DECIBEL_VOLUME LATENCY Properties: device.class = "filter" combine.slaves = "audioio.0,audioio.1" device.description = " audioio.0, audioio.1" device.icon_name = "audio-card" Formats: pcm without any syncing method, what we hear from the front-speaker is ahead of the rear-speaker (real-spear is slower for sure), our goal is that make the rear-speaker almost sync with (or catch up) the front speaker. so my question is how, is there any good way to solve it in our existing framework ? Thanks! (sorry for my bad explanation since English is not my native language) BR, Lixin </body> </html>