[FFmpeg-devel] [PATCH] jpeg2000: Initialize only once mqc arrays

[nicoinattendu at gmail.com]

From: Nicolas Bertrand <nicoinattendu at gmail.com>

Increases encoding and decoding speed
---
 libavcodec/j2kenc.c      |    2 +-
 libavcodec/jpeg2000dec.c |    1 +
 libavcodec/mqc.c         |   15 +++++++++------
 libavcodec/mqc.h         |    5 +++++
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/libavcodec/j2kenc.c b/libavcodec/j2kenc.c
index e4c84ef..48c1db8 100644
--- a/libavcodec/j2kenc.c
+++ b/libavcodec/j2kenc.c
@@ -1016,7 +1016,7 @@ static av_cold int j2kenc_init(AVCodecContext *avctx)
     }
 
     ff_jpeg2000_init_tier1_luts();
-
+    ff_mqc_init_context_tables();
     init_luts();
 
     init_quantization(s);
diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 4018dc9..e2a9a95 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -1466,6 +1466,7 @@ end:
 static void jpeg2000_init_static_data(AVCodec *codec)
 {
     ff_jpeg2000_init_tier1_luts();
+    ff_mqc_init_context_tables();
 }
 
 #define OFFSET(x) offsetof(Jpeg2000DecoderContext, x)
diff --git a/libavcodec/mqc.c b/libavcodec/mqc.c
index 288570d..f8294cd 100644
--- a/libavcodec/mqc.c
+++ b/libavcodec/mqc.c
@@ -92,14 +92,9 @@ uint16_t ff_mqc_qe [2 * 47];
 uint8_t ff_mqc_nlps[2 * 47];
 uint8_t ff_mqc_nmps[2 * 47];
 
-void ff_mqc_init_contexts(MqcState *mqc)
+void ff_mqc_init_context_tables(void)
 {
     int i;
-    memset(mqc->cx_states, 0, sizeof(mqc->cx_states));
-    mqc->cx_states[MQC_CX_UNI] = 2 * 46;
-    mqc->cx_states[MQC_CX_RL]  = 2 * 3;
-    mqc->cx_states[0]          = 2 * 4;
-
     for (i = 0; i < 47; i++) {
         ff_mqc_qe[2 * i]     =
         ff_mqc_qe[2 * i + 1] = cx_states[i].qe;
@@ -110,3 +105,11 @@ void ff_mqc_init_contexts(MqcState *mqc)
         ff_mqc_nmps[2 * i + 1] = 2 * cx_states[i].nmps + 1;
     }
 }
+
+void ff_mqc_init_contexts(MqcState *mqc)
+{
+    memset(mqc->cx_states, 0, sizeof(mqc->cx_states));
+    mqc->cx_states[MQC_CX_UNI] = 2 * 46;
+    mqc->cx_states[MQC_CX_RL]  = 2 * 3;
+    mqc->cx_states[0]          = 2 * 4;
+}
diff --git a/libavcodec/mqc.h b/libavcodec/mqc.h
index a0112d1..c0827bd 100644
--- a/libavcodec/mqc.h
+++ b/libavcodec/mqc.h
@@ -79,6 +79,11 @@ int ff_mqc_decode(MqcState *mqc, uint8_t *cxstate);
 /* common */
 
 /**
+ * MQ-coder Initialize context tables (QE, NLPS, NMPS)
+ */
+void ff_mqc_init_context_tables(void);
+
+/**
  * MQ-coder context initialisations.
  * @param mqc       MQ-coder context
  */
-- 
1.7.9.5