Platform: RK3288
OS: Android 7.1.2
Kernel: v4.4.143
问题：
HDMI输出给个别电视机时，电视机无声音
分析步骤：
1、用以下命令测试HDMI是否有输出
tinyplay 44.1k_2ch_16b_1k_15s.wav -D 0 -d 1 -c 2 -b 16 -r 44100 指令播放附件wav文件结论：该命令HDMI有声音输出
2、打开音频相关的日志输出并提供Logcat日志给RK
diff --git a/tinyalsa_hal/alsa_route.c b/tinyalsa_hal/alsa_route.cindex f28f3a6..b550b91 100755--- a/tinyalsa_hal/alsa_route.c+++ b/tinyalsa_hal/alsa_route.c@@ -43,7 +43,7 @@ #define LOG_TAG "alsa_route" -//#define LOG_NDEBUG 0+#define LOG_NDEBUG 0 #include <cutils/log.h> #include <cutils/config_utils.h>diff --git a/tinyalsa_hal/audio_hw.c b/tinyalsa_hal/audio_hw.cindex a7445ba..18164f2 100755--- a/tinyalsa_hal/audio_hw.c+++ b/tinyalsa_hal/audio_hw.c@@ -70,7 +70,7 @@ * @date 2015-08-24 */ -//#define LOG_NDEBUG 0+#define LOG_NDEBUG 0 #define LOG_TAG "AudioHardwareTiny" #include "alsa_audio.h"@@ -854,7 +854,7 @@ static int start_output_stream(struct stream_out *out) int ret = 0; int card = (int)SND_OUT_SOUND_CARD_UNKNOWN; - ALOGD("%s device: %x",__FUNCTION__, out->device);+ ALOGD("%s out->device=0x%x,out->pcm_device=0x%d n",__FUNCTION__,out->device,out->pcm_device); if (out == adev->outputs[OUTPUT_HDMI_MULTI]) { force_non_hdmi_out_standby(adev); } else if (adev->outputs[OUTPUT_HDMI_MULTI] && !adev->outputs[OUTPUT_HDMI_MULTI]->standby) {3、根据RK的方法修改如下
diff --git a/tinyalsa_hal/audio_hw.c b/tinyalsa_hal/audio_hw.cindex 0a35b80..f091c97 100755--- a/tinyalsa_hal/audio_hw.c+++ b/tinyalsa_hal/audio_hw.c@@ -644,7 +644,7 @@ static int start_output_stream(struct stream_out *out) } #endif #endif- out->pcm[PCM_CARD_HDMI] = pcm_open(PCM_CARD_HDMI, out->pcm_device,+ out->pcm[PCM_CARD_HDMI] = pcm_open(0, 1, PCM_OUT | PCM_MONOTONIC, &out->config); if (out->pcm[PCM_CARD_HDMI] && !pcm_is_ready(out->pcm[PCM_CARD_HDMI])) {原理：
1、查找头文件audio_hw.h对PCM_CARD_HDMI的声明如下
#ifdef BOX_HALint PCM_CARD = 0;int PCM_CARD_HDMI = 0;int PCM_CARD_SPDIF = 1;#elseint PCM_CARD = 0;int PCM_CARD_HDMI = 1;int PCM_CARD_SPDIF = 2;#endif如上代码对pcm设备进行了选配，根据Android.mk文件选配。
2、调试：获取当前声卡的编号 cat /proc/asound/cards
参考资源：
RK3288 -- 关于 HDMI 音频输出的两种配置