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Merged
merged 1 commit into from
Mar 24, 2025
Merged

Bluetooth: Add document to illustrate the analye procedures of a2dp. #113

merged 1 commit into from
Mar 24, 2025

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jialu522
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bug: v/53750

@jialu522 jialu522 requested a review from gzh-terry March 20, 2025 09:16
gzh-terry
gzh-terry suggested changes Mar 20, 2025
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zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

上述log中，实际传输的样本点数量为：5949440 - 5904896 = 44546，与预期接近。

1秒内音频数据的样本点数量远大于采样率时，air log中会看到密集的包，典型log如下：
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样本点数量大于采样率，和密集的包，不构成因果关系。
应该说：

通常，当音频数据在SRC端阻塞时，1秒内传输的样本点数量小于采样率。当阻塞解除后，1秒内传输的样本点数量通常大于采样率。阻塞恢复的典型log如下。

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另外，可以在这里补充样本点数量不足的例子。

zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

<img src="img/how_to_analyze_bluetooth_issues/a2dp/sniffer_avdtp_media_packet_number_abnormal.png" alt="sniffer:abnormal AVDTP media packet sequence number" width="50%">

上述log中，实际传输的样本点数量为：7395456 - 7270656 = 124800，远超预期。
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“实际传输的"->”1秒内实际传输的“

gzh-terry
gzh-terry suggested changes Mar 20, 2025
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zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

空口出现重传的原因有两种：

* 设备发送的包没收到对端的回复
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没收到->没有收到

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也请注意其他位置

zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

* 设备发送的包没收到对端的回复

* 设备发送的包收到了对端的回复，但回复的ARQN是NAK
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但回复中ARQN字段的内容是NAK

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其他地方保持一致，避免口语表述，这是专业性的体现。

zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

<img src="img/how_to_analyze_bluetooth_issues/a2dp/sniffer_no_response.png" alt="sniffer:packet with no response" width="50%">

上述log中，设备发了3次2-DH5包，前两次的包没收到对端设备的回复，SEQN值维持不变，第三次的包收到了对端设备的回复，且回复的ARQN是ACK，SEQN发生了变化，重传结束。
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"设备发送了3次2-DH5包" -> "序列号为6536的音频数据包被发送了3次"
"前两次的包" -> "第1、2次发送的数据包"
"第三次的包" -> ”第3次发送的数据包“

zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

上述log中，设备发了3次2-DH5包，前两次的包没收到对端设备的回复，SEQN值维持不变，第三次的包收到了对端设备的回复，且回复的ARQN是ACK，SEQN发生了变化，重传结束。

设备发送的包收到了对端的回复，但回复的ARQN是NAK，典型log如下：
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但回复包中的ARQN字段内容是NAK

gzh-terry
gzh-terry reviewed Mar 20, 2025
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zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

* 若应用未能发送第二耳机连接请求，建议在App侧观察未能发送的原因。

* 若应用发送了第二耳机连接请求，但未能建立AVDTP signaling连接，建议对比典型log，观察建立signaling连接中是否出现异常。
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"建立signaling连接中"->"建立signaling连接过程中"

gzh-terry
gzh-terry reviewed Mar 20, 2025
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zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

* 若Vela Media未能成功设置codec，建议在Vela Media模块观察未能设置codec的原因。

* 若Vela Media成功设置codec，建议观察[观察是否开始播放音乐](#方法观察a2dp-src是否开始播放音乐)
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建议观察[观察 -> 建议[观察

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其他几处有相似问题

gzh-terry
gzh-terry reviewed Mar 20, 2025
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zh-cn/device_dev_guide/connection/bluetooth/how_to_analyze_bluetooth_issues.md

* [观察sequence number是否连续](#方法观察air-log中的音频包序列号是否连续)

* 若air log中出问题的音频流中存在音频包序列号不连续，建议Vela蓝牙测观察音频流中音频包的序列号不连续的原因。
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蓝牙测 -> 蓝牙侧

请通篇检查

@tanghao-xiaomi tanghao-xiaomi merged commit 22ff619 into open-vela:dev Mar 24, 2025
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@gzh-terry gzh-terry gzh-terry requested changes

@xiaoxiang781216 xiaoxiang781216 xiaoxiang781216 approved these changes

@tanghao-xiaomi tanghao-xiaomi tanghao-xiaomi approved these changes

@zhangshanmin zhangshanmin Awaiting requested review from zhangshanmin

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@jialu522 @xiaoxiang781216 @gzh-terry @tanghao-xiaomi