audio: -audiodev command line option basic implementation

Audio drivers now get an Audiodev * as config paramters, instead of the
global audio_option structs.  There is some code in audio/audio_legacy.c
that converts the old environment variables to audiodev options (this
way backends do not have to worry about legacy options).  It also
contains a replacement of -audio-help, which prints out the equivalent
-audiodev based config of the currently specified environment variables.

Note that backends are not updated and still rely on environment
variables.

Also note that (due to moving try-poll from global to backend specific
option) currently ALSA and OSS will always try poll mode, regardless of
environment variables or -audiodev options.

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Message-id: e99a7cbdac0d13512743880660b2032024703e4c.1552083282.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/audio/audio.h b/audio/audio.h
index 02f29a3..64b0f76 100644
--- a/audio/audio.h
+++ b/audio/audio.h
@@ -36,12 +36,21 @@
 #define AUDIO_HOST_ENDIANNESS 0
 #endif
 
-struct audsettings {
+typedef struct audsettings {
     int freq;
     int nchannels;
     AudioFormat fmt;
     int endianness;
-};
+} audsettings;
+
+audsettings audiodev_to_audsettings(AudiodevPerDirectionOptions *pdo);
+int audioformat_bytes_per_sample(AudioFormat fmt);
+int audio_buffer_frames(AudiodevPerDirectionOptions *pdo,
+                        audsettings *as, int def_usecs);
+int audio_buffer_samples(AudiodevPerDirectionOptions *pdo,
+                         audsettings *as, int def_usecs);
+int audio_buffer_bytes(AudiodevPerDirectionOptions *pdo,
+                       audsettings *as, int def_usecs);
 
 typedef enum {
     AUD_CNOTIFY_ENABLE,
@@ -81,7 +90,6 @@
 void AUD_vlog (const char *cap, const char *fmt, va_list ap) GCC_FMT_ATTR(2, 0);
 void AUD_log (const char *cap, const char *fmt, ...) GCC_FMT_ATTR(2, 3);
 
-void AUD_help (void);
 void AUD_register_card (const char *name, QEMUSoundCard *card);
 void AUD_remove_card (QEMUSoundCard *card);
 CaptureVoiceOut *AUD_add_capture (
@@ -163,4 +171,8 @@
 void audio_sample_from_uint64(void *samples, int pos,
                             uint64_t left, uint64_t right);
 
+void audio_parse_option(const char *opt);
+void audio_init_audiodevs(void);
+void audio_legacy_help(void);
+
 #endif /* QEMU_AUDIO_H */