[vlc-devel] [RFC PATCH 5/6] decoder: add audio decoder fallback
Thomas Guillem
thomas at gllm.fr
Fri Jul 1 18:14:54 CEST 2016
An audio decoder module will be able to request that an audio passthrough
feature. If such module fails in aout_update_format() (the audio_output can't
do SPDIF), the DecoderThread will try a new decoder module and will refuse any
module that need audio passthrough.
The audio device change callback is also listened in order to restart decoders
when an audio device change.
---
include/vlc_codec.h | 9 ++++++
src/input/decoder.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++--
src/libvlccore.sym | 1 +
3 files changed, 92 insertions(+), 2 deletions(-)
diff --git a/include/vlc_codec.h b/include/vlc_codec.h
index 132d935..d250281 100644
--- a/include/vlc_codec.h
+++ b/include/vlc_codec.h
@@ -366,6 +366,15 @@ static inline int decoder_UpdateAudioFormat( decoder_t *dec )
return -1;
}
+/**
+ * This function asks to the decoder if it's possible for the module to do
+ * audio passthrough
+ * @param b_request true to request, false to cancel a previous successfull
+ * request
+ * @return true if the module can do audio passthrough
+ */
+VLC_API bool decoder_RequestAudioPassthrough( decoder_t *dec, bool b_request );
+
static inline void decoder_AddState( decoder_t *dec, int state )
{
atomic_fetch_or( &dec->state, state );
diff --git a/src/input/decoder.c b/src/input/decoder.c
index 5cf2b63..20de6e5 100644
--- a/src/input/decoder.c
+++ b/src/input/decoder.c
@@ -54,6 +54,14 @@
#include "../video_output/vout_control.h"
+enum audio_passthrough
+{
+ AUDIO_PASSTHROUGH_DISABLED,
+ AUDIO_PASSTHROUGH_AVAILABLE,
+ AUDIO_PASSTHROUGH_ENABLED,
+ AUDIO_PASSTHROUGH_FAILED,
+};
+
struct decoder_owner_sys_t
{
input_thread_t *p_input;
@@ -80,6 +88,8 @@ struct decoder_owner_sys_t
/* */
bool b_fmt_description;
vlc_meta_t *p_description;
+ atomic_bool aout_device_changed;
+ enum audio_passthrough audio_passthrough;
/* fifo */
block_fifo_t *p_fifo;
@@ -230,6 +240,18 @@ static vout_thread_t *aout_request_vout( void *p_private,
return p_vout;
}
+
+static int aout_device_changed( vlc_object_t *p_obj, const char *p_var,
+ vlc_value_t prev, vlc_value_t cur, void *p_data)
+{
+ (void) p_obj; (void) p_var; (void) prev; (void) cur;
+ decoder_t *p_dec = p_data;
+ decoder_owner_sys_t *p_owner = p_dec->p_owner;
+ atomic_store( &p_owner->aout_device_changed, true );
+
+ return VLC_SUCCESS;
+}
+
static int aout_update_format( decoder_t *p_dec )
{
decoder_owner_sys_t *p_owner = p_dec->p_owner;
@@ -243,6 +265,7 @@ static int aout_update_format( decoder_t *p_dec )
vlc_mutex_lock( &p_owner->lock );
p_owner->p_aout = NULL;
vlc_mutex_unlock( &p_owner->lock );
+ var_DelCallback( p_aout, "device", aout_device_changed, p_dec );
aout_DecDelete( p_aout );
input_resource_PutAout( p_owner->p_resource, p_aout );
@@ -288,6 +311,8 @@ static int aout_update_format( decoder_t *p_dec )
input_resource_PutAout( p_owner->p_resource, p_aout );
p_aout = NULL;
}
+ else
+ var_AddCallback( p_aout, "device", aout_device_changed, p_dec );
}
vlc_mutex_lock( &p_owner->lock );
@@ -560,6 +585,26 @@ block_t *decoder_NewAudioBuffer( decoder_t *dec, int samples )
return block;
}
+bool decoder_RequestAudioPassthrough( decoder_t *p_dec, bool b_request )
+{
+ decoder_owner_sys_t *p_owner = p_dec->p_owner;
+
+ if( b_request )
+ {
+ if( p_owner->audio_passthrough == AUDIO_PASSTHROUGH_AVAILABLE )
+ {
+ p_owner->audio_passthrough = AUDIO_PASSTHROUGH_ENABLED;
+ return true;
+ }
+ }
+ else
+ {
+ assert( p_owner->audio_passthrough == AUDIO_PASSTHROUGH_ENABLED );
+ p_owner->audio_passthrough = AUDIO_PASSTHROUGH_AVAILABLE;
+ }
+ return false;
+}
+
subpicture_t *decoder_NewSubpicture( decoder_t *p_decoder,
const subpicture_updater_t *p_dyn )
{
@@ -1328,8 +1373,38 @@ static void DecoderProcess( decoder_t *p_dec, block_t *p_block )
{
decoder_owner_sys_t *p_owner = p_dec->p_owner;
- if( atomic_load( &p_dec->state ) & DECODER_STATE_ERROR )
- goto error;
+ bool b_audio_passthrough_failed = false;
+ int i_error = atomic_load( &p_dec->state ) & DECODER_STATE_ERROR;
+ if( i_error != 0 )
+ {
+ if( p_owner->audio_passthrough == AUDIO_PASSTHROUGH_ENABLED
+ && i_error == DECODER_STATE_ERROR_OUTPUT )
+ b_audio_passthrough_failed = true;
+ else
+ goto error;
+ }
+
+ if( p_owner->audio_passthrough != AUDIO_PASSTHROUGH_DISABLED
+ && ( atomic_exchange( &p_owner->aout_device_changed, false )
+ || b_audio_passthrough_failed ) )
+ {
+ msg_Warn( p_dec, "Restarting decoder due since %s",
+ b_audio_passthrough_failed ?
+ "there is no available SPDIF output" :
+ "the audio device changed" );
+
+ UnloadDecoder( p_dec, false );
+
+ /* If passthrough previously failed, we don't want to retry, except if
+ * the device changed */
+ p_owner->audio_passthrough = b_audio_passthrough_failed ?
+ AUDIO_PASSTHROUGH_FAILED :
+ AUDIO_PASSTHROUGH_AVAILABLE;
+
+ if( LoadDecoder( p_dec, false, NULL ) )
+ goto error;
+ atomic_fetch_and( &p_dec->state, ~DECODER_STATE_ERROR_OUTPUT );
+ }
if( p_block )
{
@@ -1580,6 +1655,10 @@ static decoder_t * CreateDecoder( vlc_object_t *p_parent,
p_owner->b_draining = false;
atomic_init( &p_owner->drained, false );
p_owner->b_idle = false;
+ p_owner->audio_passthrough =
+ fmt->i_cat == AUDIO_ES && var_InheritBool( p_dec, "spdif" ) ?
+ AUDIO_PASSTHROUGH_AVAILABLE : AUDIO_PASSTHROUGH_DISABLED;
+ atomic_init( &p_owner->aout_device_changed, false );
es_format_Init( &p_owner->fmt, UNKNOWN_ES, 0 );
@@ -1698,6 +1777,7 @@ static void DeleteDecoder( decoder_t * p_dec )
if( p_owner->p_aout )
{
/* TODO: REVISIT gap-less audio */
+ var_DelCallback( p_owner->p_aout, "device", aout_device_changed, p_dec );
aout_DecFlush( p_owner->p_aout, false );
aout_DecDelete( p_owner->p_aout );
input_resource_PutAout( p_owner->p_resource, p_owner->p_aout );
diff --git a/src/libvlccore.sym b/src/libvlccore.sym
index 89e74f8..2a1f286 100644
--- a/src/libvlccore.sym
+++ b/src/libvlccore.sym
@@ -82,6 +82,7 @@ decoder_GetDisplayRate
decoder_GetInputAttachments
decoder_NewAudioBuffer
decoder_NewSubpicture
+decoder_RequestAudioPassthrough
decoder_SynchroChoose
decoder_SynchroDate
decoder_SynchroDecode
--
2.8.1
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