[FFmpeg-devel] [PATCH 2/2] lavc/pcm_tablegen: always generate tables at runtime.

Ganesh Ajjanagadde gajjanagadde at gmail.com
Thu Dec 31 05:34:56 CET 2015


Previous commit has sped up pcm_tablegen slightly, and table generation
of the alaw and mulaw tables is ~ 20k cycles. Thus, these tables can
always be generated at runtime.

Tested with/without --enable-hardcoded-tables.

Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
---
 libavcodec/Makefile       |  4 +---
 libavcodec/pcm_tablegen.c | 39 ---------------------------------------
 libavcodec/pcm_tablegen.h |  6 ------
 3 files changed, 1 insertion(+), 48 deletions(-)
 delete mode 100644 libavcodec/pcm_tablegen.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 0717d0a..568bc8a 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -978,7 +978,6 @@ HOSTPROGS = aacps_tablegen                                              \
             dv_tablegen                                                 \
             motionpixels_tablegen                                       \
             mpegaudio_tablegen                                          \
-            pcm_tablegen                                                \
             qdm2_tablegen                                               \
             sinewin_tablegen                                            \
             sinewin_fixed_tablegen                                      \
@@ -1003,7 +1002,7 @@ endif
 GEN_HEADERS = cbrt_tables.h cbrt_fixed_tables.h aacps_tables.h aacps_fixed_tables.h \
               dv_tables.h     \
               sinewin_tables.h sinewin_fixed_tables.h mpegaudio_tables.h motionpixels_tables.h \
-              pcm_tables.h qdm2_tables.h
+              qdm2_tables.h
 GEN_HEADERS := $(addprefix $(SUBDIR), $(GEN_HEADERS))
 
 $(GEN_HEADERS): $(SUBDIR)%_tables.h: $(SUBDIR)%_tablegen$(HOSTEXESUF)
@@ -1021,6 +1020,5 @@ $(SUBDIR)sinewin_fixed.o: $(SUBDIR)sinewin_fixed_tables.h
 $(SUBDIR)mpegaudiodec_fixed.o: $(SUBDIR)mpegaudio_tables.h
 $(SUBDIR)mpegaudiodec_float.o: $(SUBDIR)mpegaudio_tables.h
 $(SUBDIR)motionpixels.o: $(SUBDIR)motionpixels_tables.h
-$(SUBDIR)pcm.o: $(SUBDIR)pcm_tables.h
 $(SUBDIR)qdm2.o: $(SUBDIR)qdm2_tables.h
 endif
diff --git a/libavcodec/pcm_tablegen.c b/libavcodec/pcm_tablegen.c
deleted file mode 100644
index bf8e7fb..0000000
--- a/libavcodec/pcm_tablegen.c
+++ /dev/null
@@ -1,39 +0,0 @@
-/*
- * Generate a header file for hardcoded PCM tables
- *
- * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger at gmx.de>
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <stdlib.h>
-#define CONFIG_HARDCODED_TABLES 0
-#include "pcm_tablegen.h"
-#include "tableprint.h"
-
-int main(void)
-{
-    pcm_alaw_tableinit();
-    pcm_ulaw_tableinit();
-
-    write_fileheader();
-
-    WRITE_ARRAY("static const", uint8_t, linear_to_alaw);
-    WRITE_ARRAY("static const", uint8_t, linear_to_ulaw);
-
-    return 0;
-}
diff --git a/libavcodec/pcm_tablegen.h b/libavcodec/pcm_tablegen.h
index 7269977..d73a14e 100644
--- a/libavcodec/pcm_tablegen.h
+++ b/libavcodec/pcm_tablegen.h
@@ -72,11 +72,6 @@ static av_cold int ulaw2linear(unsigned char u_val)
         return (u_val & SIGN_BIT) ? (BIAS - t) : (t - BIAS);
 }
 
-#if CONFIG_HARDCODED_TABLES
-#define pcm_alaw_tableinit()
-#define pcm_ulaw_tableinit()
-#include "libavcodec/pcm_tables.h"
-#else
 /* 16384 entries per table */
 static uint8_t linear_to_alaw[16384];
 static uint8_t linear_to_ulaw[16384];
@@ -114,6 +109,5 @@ static void pcm_ulaw_tableinit(void)
 {
     build_xlaw_table(linear_to_ulaw, ulaw2linear, 0xff);
 }
-#endif /* CONFIG_HARDCODED_TABLES */
 
 #endif /* AVCODEC_PCM_TABLEGEN_H */
-- 
2.6.4



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