[vlc-devel] [PATCH 09/31] decoder: split the decoder format update in 2 parts

[Steve Lhomme]

The first part is to create the decoder device.
The second part is to create the display module (or other depending on the
decoder owner).

Turn decoder_UpdateVideoFormat() is calling the two new functions.
---
 include/vlc_codec.h         | 38 +++++++++++++++++++++++++++++++++++++
 src/input/decoder_helpers.c | 20 +++++++++++++++++++
 src/libvlccore.sym          |  2 ++
 3 files changed, 60 insertions(+)

diff --git a/include/vlc_codec.h b/include/vlc_codec.h
index 28a65846d9e..8d2680f1965 100644
--- a/include/vlc_codec.h
+++ b/include/vlc_codec.h
@@ -49,6 +49,7 @@ struct decoder_owner_callbacks
     {
         struct
         {
+            int         (*hold_device)( decoder_t *, vlc_decoder_device ** );
             int         (*format_update)( decoder_t * );
 
             /* cf. decoder_NewPicture, can be called from any decoder thread */
@@ -253,6 +254,43 @@ struct encoder_t
  * @{
  */
 
+/**
+ * Creates/Updates the output decoder device.
+ *
+ * This function notifies the video output pipeline of a new video output
+ * format (fmt_out.video). If there was no decoder device so far or a new
+ * decoder device is required, a new decoder device will be set up.
+ * decoder_UpdateVideoOutput() can then be used.
+ *
+ * If the format is unchanged, this function has no effects and returns zero.
+ *
+ * \param dec the decoder object
+ * \param pp_dec_dev the received of the held decoder device, NULL not to get one
+ *
+ * \note
+ * This function is not reentrant.
+ *
+ * @return 0 if the video output was set up successfully, -1 otherwise.
+ */
+VLC_API int decoder_HoldDecoderDevice( decoder_t *dec, vlc_decoder_device **pp_dec_dev );
+
+/**
+ * Creates/Updates the rest of the video output pipeline.
+ *
+ * After a call to decoder_HoldDecoderDevice() this function notifies the
+ * video output pipeline of a new video output format (fmt_out.video). If there
+ * was no video output from the decoder so far, a new decoder video output will
+ * be set up. decoder_NewPicture() can then be used to allocate picture buffers.
+ *
+ * If the format is unchanged, this function has no effects and returns zero.
+ *
+ * \note
+ * This function is not reentrant.
+ *
+ * @return 0 if the video output was set up successfully, -1 otherwise.
+ */
+VLC_API int decoder_UpdateVideoOutput( decoder_t *dec );
+
 /**
  * Updates the video output format.
  *
diff --git a/src/input/decoder_helpers.c b/src/input/decoder_helpers.c
index 6d5b0050ed7..51e097961b9 100644
--- a/src/input/decoder_helpers.c
+++ b/src/input/decoder_helpers.c
@@ -76,6 +76,26 @@ void decoder_Destroy( decoder_t *p_dec )
 }
 
 int decoder_UpdateVideoFormat( decoder_t *dec )
+{
+    int res = decoder_HoldDecoderDevice( dec, NULL );
+    if (res == 0)
+        res = decoder_UpdateVideoOutput( dec );
+    return res;
+}
+
+int decoder_HoldDecoderDevice( decoder_t *dec, vlc_decoder_device **pp_dec_dev )
+{
+    vlc_assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
+    if ( unlikely(dec->fmt_in.i_cat != VIDEO_ES || dec->cbs == NULL ) )
+        return -1;
+
+    if ( dec->cbs->video.hold_device == NULL )
+        return 0; /* TODO make it mandatory for all decoder owners */
+
+    return dec->cbs->video.hold_device( dec, pp_dec_dev );
+}
+
+int decoder_UpdateVideoOutput( decoder_t *dec )
 {
     vlc_assert( dec->fmt_in.i_cat == VIDEO_ES && dec->cbs != NULL );
     if ( unlikely(dec->fmt_in.i_cat != VIDEO_ES || dec->cbs == NULL ||
diff --git a/src/libvlccore.sym b/src/libvlccore.sym
index e5241c411d0..fb2952ee5ef 100644
--- a/src/libvlccore.sym
+++ b/src/libvlccore.sym
@@ -82,6 +82,8 @@ decoder_Destroy
 decoder_AbortPictures
 decoder_NewAudioBuffer
 decoder_UpdateVideoFormat
+decoder_HoldDecoderDevice
+decoder_UpdateVideoOutput
 vlc_decoder_device_Hold
 vlc_decoder_device_Release
 demux_PacketizerDestroy
-- 
2.17.1