Merge remote-tracking branch 'qatar/master'

* qatar/master:
  fate: add dxtory test
  adx_parser: rewrite.
  adxdec: Validate channel count to fix a division by zero.
  adxdec: Do not require extradata.
  cmdutils: K&R reformatting cosmetics
  alacdec: implement the 2-pass prediction type.
  alacenc: implement the 2-pass prediction type.
  alacenc: do not generate invalid multi-channel ALAC files
  alacdec: fill in missing or guessed info about the extradata format.
  utvideo: proper median prediction for interlaced videos
  lavu: bump lavu minor for av_popcount64
  dca: K&R formatting cosmetics
  dct: K&R formatting cosmetics
  lavf: flush decoders in avformat_find_stream_info().
  win32: detect number of CPUs using affinity
  Add av_popcount64
  snow: Restore three mistakenly removed casts.

Conflicts:
	cmdutils.c
	doc/APIchanges
	libavcodec/adx_parser.c
	libavcodec/adxdec.c
	libavcodec/alacenc.c
	libavutil/avutil.h
	tests/fate/screen.mak

Merged-by: Michael Niedermayer <michaelni@gmx.at>

1 files changed, 15 insertions, 3 deletions

diff --git a/libavcodec/alacenc.c b/libavcodec/alacenc.c
index 305a5b825b..e8d1bc03f2 100644
--- a/libavcodec/alacenc.c
+++ b/libavcodec/alacenc.c
@@ -348,6 +348,7 @@ static void alac_entropy_coder(AlacEncodeContext *s)
 static void write_compressed_frame(AlacEncodeContext *s)
 {
     int i, j;
+    int prediction_type = 0;
 
     if (s->avctx->channels == 2)
         alac_stereo_decorrelation(s);
@@ -358,7 +359,7 @@ static void write_compressed_frame(AlacEncodeContext *s)
 
         calc_predictor_params(s, i);
 
-        put_bits(&s->pbctx, 4, 0);  // prediction type : currently only type 0 has been RE'd
+        put_bits(&s->pbctx, 4, prediction_type);
         put_bits(&s->pbctx, 4, s->lpc[i].lpc_quant);
 
         put_bits(&s->pbctx, 3, s->rc.rice_modifier);
@@ -373,6 +374,14 @@ static void write_compressed_frame(AlacEncodeContext *s)
 
     for (i = 0; i < s->avctx->channels; i++) {
         alac_linear_predictor(s, i);
+
+        // TODO: determine when this will actually help. for now it's not used.
+        if (prediction_type == 15) {
+            // 2nd pass 1st order filter
+            for (j = s->avctx->frame_size - 1; j > 0; j--)
+                s->predictor_buf[j] -= s->predictor_buf[j - 1];
+        }
+
         alac_entropy_coder(s);
     }
 }
@@ -391,8 +400,11 @@ static av_cold int alac_encode_init(AVCodecContext *avctx)
         return -1;
     }
 
-    if(avctx->channels > 2) {
-        av_log(avctx, AV_LOG_ERROR, "channels > 2 not supported\n");
+    /* TODO: Correctly implement multi-channel ALAC.
+             It is similar to multi-channel AAC, in that it has a series of
+             single-channel (SCE), channel-pair (CPE), and LFE elements. */
+    if (avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR, "only mono or stereo input is currently supported\n");
         return AVERROR_PATCHWELCOME;
     }