doc:appunti:linux:audio:audio_recording_tmb113_e
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doc:appunti:linux:audio:audio_recording_tmb113_e [2020/12/28 07:43] – [Setting recording volume with PulseAudio] niccolo | doc:appunti:linux:audio:audio_recording_tmb113_e [2020/12/28 16:09] (current) – [Recording with PulseAudio parecord] niccolo | ||
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- | ====== Audio recording with the Acer Travelmate | + | ====== Audio recording with the Acer TravelMate |
- | How to record audio using a **wireless microphone** connected to the audio jack of an **Acer | + | {{acer-travelmate-wireless-microphone.jpg? |
+ | How to record audio using a **wireless microphone** connected to the audio jack of an **Acer | ||
+ | |||
+ | The microphone is a **[[wp> | ||
+ | |||
+ | ===== Electrical connection ===== | ||
+ | |||
+ | I used an headset/ | ||
+ | |||
+ | ^ 1/4" TS female jack ^ Signal | ||
+ | | | Not connected | ||
+ | | | Not connected | ||
+ | | **Sleeve** | ||
+ | | **Tip** | ||
===== Problem detecting the external microphone ===== | ===== Problem detecting the external microphone ===== | ||
Line 73: | Line 86: | ||
===== Setting the recording volume with PulseAudio ===== | ===== Setting the recording volume with PulseAudio ===== | ||
- | I used the PulseAudio mixer **pavucontrol** to set the recording volume level: it turned out that a value of **16463** (corresponding to 25% of the slider, or -36.00 dB) is the best setting for normal speach. At the ALSA level (lower level interface used by PylseAudio) it means a **Capture** level of **100** and a **Mic Boost** of **0**. This is a table of value correspondence between PulseAudio and ALSA (notice that it is specific to this PCI sound card): | + | I used the PulseAudio mixer **pavucontrol** to set the recording volume level: it turned out that a value of **16463** (corresponding to 25% of the slider, or -36.00 dB) is the best setting for normal speach. At the ALSA level (lower level interface used by PulseAudio) it means a **Capture** level of **100** and a **Mic Boost** of **0**. This is a table of value correspondence between PulseAudio and ALSA (notice that it is specific to this PCI sound card): |
^ ALSA ^ PulseAudio | ^ ALSA ^ PulseAudio | ||
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| Capture 100, Mic Boost 20 | Volume: 26092 / 40% / -24.00 dB | | | Capture 100, Mic Boost 20 | Volume: 26092 / 40% / -24.00 dB | | ||
| Capture 100, Mic Boost 51 | Volume: 41353 / 63% / -12.00 dB | | | Capture 100, Mic Boost 51 | Volume: 41353 / 63% / -12.00 dB | | ||
+ | |||
+ | You can check the correspondence between **PulseAudio** and **ALSA** levels by executing **alsamixer**, | ||
+ | |||
+ | ===== Recording with PulseAudio parecord ===== | ||
+ | |||
+ | I want to use the **PulseAudio** subsystem to record the audio; I don't want to use the ALSA kernel-level interface, which needs direct and exclusive access to the device. | ||
+ | |||
+ | Using the command **pacmd list-sources** you can discover the **name** of the **device.class** of type **sound**, the current **volume** level, the **base volume** and the **ports** (microphones) availables. | ||
+ | |||
+ | |||
+ | The recording volume should be a vaule between the **base volume** and **65536** (corresponding to 100%, or 0.00 dB). Every different hardware should be tested to find the best settings to get a clear and loud sound, but to avoid clipping (out of scale samples). | ||
+ | |||
+ | < | ||
+ | pacmd list-sources | ||
+ | 2 source(s) available. | ||
+ | index: 0 | ||
+ | name: < | ||
+ | ... | ||
+ | properties: | ||
+ | device.description = " | ||
+ | device.class = " | ||
+ | ... | ||
+ | * index: 1 | ||
+ | name: < | ||
+ | volume: front-left: 26092 / 40% / -24.00 dB, | ||
+ | base volume: 5206 / 8% / -66.00 dB | ||
+ | ... | ||
+ | properties: | ||
+ | device.class = " | ||
+ | ... | ||
+ | ports: | ||
+ | analog-input-internal-mic: | ||
+ | ... | ||
+ | analog-input-mic: | ||
+ | active port: < | ||
+ | </ | ||
+ | |||
+ | **Beware** that with the audio card of the TMB113-E, the port **analog-input-mic** refers to the external microphone when that one is connected (or forcibly connected by hdajackretask), | ||
+ | |||
+ | Once you understand the output of **pacmd list-sources**, | ||
+ | |||
+ | <code bash> | ||
+ | #!/bin/sh | ||
+ | SOURCE=' | ||
+ | PORT=' | ||
+ | VOLUME=16463 | ||
+ | pacmd set-default-source " | ||
+ | pacmd set-source-port " | ||
+ | pacmd set-source-volume " | ||
+ | pacmd set-source-mute " | ||
+ | parecord --verbose --device=" | ||
+ | </ | ||
+ | |||
+ | The result is a **44100 Hz, 16 bit little-endian, | ||
===== Microphone plug/unplug events ===== | ===== Microphone plug/unplug events ===== |
doc/appunti/linux/audio/audio_recording_tmb113_e.txt · Last modified: 2020/12/28 16:09 by niccolo