downmix support for ffmpeg audio sources

now we can eat our own dogfood. i.e. aac 6ch discrete input now works,
along with any other multi-channel audio ffmpeg can toss at us.


git-svn-id: svn://svn.handbrake.fr/HandBrake/trunk@3182 b64f7644-9d1e-0410-96f1-a4d463321fa5

1 files changed, 41 insertions, 0 deletions

diff --git a/libhb/downmix.h b/libhb/downmix.h
new file mode 100644
index 000000000..f9710488b
--- /dev/null
+++ b/libhb/downmix.h
@@ -0,0 +1,41 @@
+/* $Id: downmix.h,v 1.51 2005/11/04 13:09:40 stebbins Exp $
+
+   This file is part of the HandBrake source code.
+   Homepage: <http://handbrake.fr/>.
+   It may be used under the terms of the GNU General Public License. */
+
+#ifndef DOWNMIX_H
+#define DOWNMIX_H
+
+typedef float hb_sample_t;
+
+typedef struct
+{
+    int            mode_in;
+    int            mode_out;
+    int            nchans_in;
+    int            nchans_out;
+    hb_sample_t    matrix[8][8];
+    hb_sample_t    clev;
+    hb_sample_t    slev;
+    hb_sample_t    level;
+    hb_sample_t    bias;
+} hb_downmix_t;
+
+// For convenience, a map to convert smpte channel layout
+// to QuickTime channel layout.
+// Map Indicies are mode, lfe, channel respectively
+extern int hb_smpte_chan_map[10][2][8];
+extern int hb_ac3_chan_map[10][2][8];
+
+hb_downmix_t * hb_downmix_init(int layout, int mixdown);
+void hb_downmix_close( hb_downmix_t **downmix );
+int hb_downmix_set_mode( hb_downmix_t * downmix, int layout, int mixdown );
+void hb_downmix_set_level( hb_downmix_t * downmix, hb_sample_t clev, hb_sample_t slev, hb_sample_t level );
+void hb_downmix_adjust_level( hb_downmix_t * downmix );
+void hb_downmix_set_bias( hb_downmix_t * downmix, hb_sample_t bias );
+void hb_downmix( hb_downmix_t * downmix, hb_sample_t * dst, hb_sample_t * src, int nsamples);
+void hb_layout_remap( int (*layouts)[2][8], hb_sample_t * samples, int layout, int nsamples );
+int hb_need_downmix( int layout, int mixdown );
+
+#endif /* DOWNMIX_H */