Add --audio-codec=raw option

Add support for raw (PCM S16 LE) audio codec (a decoder is included in
FFmpeg).

Even if it consumes more bandwidth, it provides a lower latency.

PR #3757 <#3757>

Author: rom1v

app/data/bash-completion/scrcpy

@@ -78,7 +78,7 @@ _scrcpy() {
             return
             ;;
         --audio-codec)
-            COMPREPLY=($(compgen -W 'opus aac' -- "$cur"))
+            COMPREPLY=($(compgen -W 'raw opus aac' -- "$cur"))
             return
             ;;
         --lock-video-orientation)

app/data/zsh-completion/_scrcpy

@@ -10,7 +10,7 @@ local arguments
 arguments=(
     '--always-on-top[Make scrcpy window always on top \(above other windows\)]'
     '--audio-bit-rate=[Encode the audio at the given bit-rate]'
-    '--audio-codec=[Select the audio codec]:codec:(opus aac)'
+    '--audio-codec=[Select the audio codec]:codec:(raw opus aac)'
     '--audio-codec-options=[Set a list of comma-separated key\:type=value options for the device audio encoder]'
     '--audio-encoder=[Use a specific MediaCodec audio encoder]'
     {-b,--video-bit-rate=}'[Encode the video at the given bit-rate]'

app/scrcpy.1

@@ -33,7 +33,7 @@ Default is 0 (no buffering).
 
 .TP
 .BI "\-\-audio\-codec " name
-Select an audio codec (opus or aac).
+Select an audio codec (raw, opus or aac).
 
 Default is opus.
 

app/src/cli.c

@@ -132,7 +132,7 @@ static const struct sc_option options[] = {
         .longopt_id = OPT_AUDIO_CODEC,
         .longopt = "audio-codec",
         .argdesc = "name",
-        .text = "Select an audio codec (opus or aac).\n"
+        .text = "Select an audio codec (raw, opus or aac).\n"
                 "Default is opus.",
     },
     {
@@ -1506,6 +1506,10 @@ parse_video_codec(const char *optarg, enum sc_codec *codec) {
 
 static bool
 parse_audio_codec(const char *optarg, enum sc_codec *codec) {
+    if (!strcmp(optarg, "raw")) {
+        *codec = SC_CODEC_RAW;
+        return true;
+    }
     if (!strcmp(optarg, "opus")) {
         *codec = SC_CODEC_OPUS;
         return true;
@@ -1514,7 +1518,7 @@ parse_audio_codec(const char *optarg, enum sc_codec *codec) {
         *codec = SC_CODEC_AAC;
         return true;
     }
-    LOGE("Unsupported audio codec: %s (expected opus or aac)", optarg);
+    LOGE("Unsupported audio codec: %s (expected raw, opus or aac)", optarg);
     return false;
 }
 
@@ -1912,6 +1916,12 @@ parse_args_with_getopt(struct scrcpy_cli_args *args, int argc, char *argv[],
         }
     }
 
+    if (opts->record_filename && opts->audio_codec == SC_CODEC_RAW) {
+        LOGW("Recording does not support RAW audio codec, automatically "
+             "switching to --audio-codec=opus");
+        opts->audio_codec = SC_CODEC_OPUS;
+    }
+
     if (!opts->control) {
         if (opts->turn_screen_off) {
             LOGE("Could not request to turn screen off if control is disabled");

app/src/demuxer.c

@@ -23,6 +23,7 @@ sc_demuxer_to_avcodec_id(uint32_t codec_id) {
 #define SC_CODEC_ID_H264 UINT32_C(0x68323634) // "h264" in ASCII
 #define SC_CODEC_ID_H265 UINT32_C(0x68323635) // "h265" in ASCII
 #define SC_CODEC_ID_AV1 UINT32_C(0x00617631) // "av1" in ASCII
+#define SC_CODEC_ID_RAW UINT32_C(0x00726177) // "raw" in ASCII
 #define SC_CODEC_ID_OPUS UINT32_C(0x6f707573) // "opus" in ASCII
 #define SC_CODEC_ID_AAC UINT32_C(0x00616163) // "aac in ASCII"
     switch (codec_id) {
@@ -32,6 +33,8 @@ sc_demuxer_to_avcodec_id(uint32_t codec_id) {
             return AV_CODEC_ID_HEVC;
         case SC_CODEC_ID_AV1:
             return AV_CODEC_ID_AV1;
+        case SC_CODEC_ID_RAW:
+            return AV_CODEC_ID_PCM_S16LE;
         case SC_CODEC_ID_OPUS:
             return AV_CODEC_ID_OPUS;
         case SC_CODEC_ID_AAC:

app/src/options.h

@@ -27,6 +27,7 @@ enum sc_codec {
     SC_CODEC_H264,
     SC_CODEC_H265,
     SC_CODEC_AV1,
+    SC_CODEC_RAW,
     SC_CODEC_OPUS,
     SC_CODEC_AAC,
 };

app/src/server.c

@@ -169,6 +169,8 @@ sc_server_get_codec_name(enum sc_codec codec) {
             return "h265";
         case SC_CODEC_AV1:
             return "av1";
+        case SC_CODEC_RAW:
+            return "raw";
         case SC_CODEC_OPUS:
             return "opus";
         case SC_CODEC_AAC: