[Ffmpeg-devel] [patch] constify read-only datastructures

Stefan Huehner stefan
Tue Jun 20 23:53:31 CEST 2006


On Tue, Jun 20, 2006 at 11:43:54PM +0200, Lo?c Le Loarer wrote:
> Le Tuesday 20 June 2006 ? 23:04:00 +0200, Stefan Huehner a ?crit:
> > Hi,
> > 
> > Additionally two unused variables in nut.c and avidec.c were removed.
> > 
> > Index: libavformat/avidec.c
> > ===================================================================
> > --- libavformat/avidec.c	(revision 5504)
> > +++ libavformat/avidec.c	(working copy)
> > @@ -138,7 +138,6 @@
> >              last_pos= pos;
> >          }else{
> >              int64_t offset= get_le64(pb);
> > -            int size      = get_le32(pb);
> >              int duration  = get_le32(pb);
> >              int64_t pos= url_ftell(pb);
> 
> This also remove the get_le32(pb) call, which will probably break
> something...

You are correct. I had not checked for the skip_bits side-effekt of the
get_le32 call.

Attached is a modified version of the patch which backs out this change
(Only the change to avidec.c was removed from the diff)

Regards,
Stefan

-------------- next part --------------
Index: libavcodec/qdm2data.h
===================================================================
--- libavcodec/qdm2data.h	(revision 5505)
+++ libavcodec/qdm2data.h	(working copy)
@@ -32,18 +32,18 @@
 /** VLC TABLES **/
 
 /* values in this table range from -1..23; adjust retrieved value by -1 */
-static uint16_t vlc_tab_level_huffcodes[24] = {
+static const uint16_t vlc_tab_level_huffcodes[24] = {
     0x037c, 0x0004, 0x003c, 0x004c, 0x003a, 0x002c, 0x001c, 0x001a,
     0x0024, 0x0014, 0x0001, 0x0002, 0x0000, 0x0003, 0x0007, 0x0005,
     0x0006, 0x0008, 0x0009, 0x000a, 0x000c, 0x00fc, 0x007c, 0x017c
 };
 
-static uint8_t vlc_tab_level_huffbits[24] = {
+static const uint8_t vlc_tab_level_huffbits[24] = {
     10, 6, 7, 7, 6, 6, 6, 6, 6, 5, 4, 4, 4, 3, 3, 3, 3, 4, 4, 5, 7, 8, 9, 10
 };
 
 /* values in this table range from -1..36; adjust retrieved value by -1 */
-static uint16_t vlc_tab_diff_huffcodes[37] = {
+static const uint16_t vlc_tab_diff_huffcodes[37] = {
     0x1c57, 0x0004, 0x0000, 0x0001, 0x0003, 0x0002, 0x000f, 0x000e,
     0x0007, 0x0016, 0x0037, 0x0027, 0x0026, 0x0066, 0x0006, 0x0097,
     0x0046, 0x01c6, 0x0017, 0x0786, 0x0086, 0x0257, 0x00d7, 0x0357,
@@ -51,111 +51,111 @@
     0x0b86, 0x0000, 0x1457, 0x0000, 0x0457
 };
 
-static uint8_t vlc_tab_diff_huffbits[37] = {
+static const uint8_t vlc_tab_diff_huffbits[37] = {
     13, 3, 3, 2, 3, 3, 4, 4, 6, 5, 6, 6, 7, 7, 8, 8,
     8, 9, 8, 11, 9, 10, 8, 10, 9, 12, 10, 0, 10, 13, 11, 0,
     12, 0, 13, 0, 13
 };
 
 /* values in this table range from -1..5; adjust retrieved value by -1 */
-static uint8_t vlc_tab_run_huffcodes[6] = {
+static const uint8_t vlc_tab_run_huffcodes[6] = {
     0x1f, 0x00, 0x01, 0x03, 0x07, 0x0f
 };
 
-static uint8_t vlc_tab_run_huffbits[6] = {
+static const uint8_t vlc_tab_run_huffbits[6] = {
     5, 1, 2, 3, 4, 5
 };
 
 /* values in this table range from -1..19; adjust retrieved value by -1 */
-static uint16_t vlc_tab_tone_level_idx_hi1_huffcodes[20] = {
+static const uint16_t vlc_tab_tone_level_idx_hi1_huffcodes[20] = {
     0x5714, 0x000c, 0x0002, 0x0001, 0x0000, 0x0004, 0x0034, 0x0054,
     0x0094, 0x0014, 0x0114, 0x0214, 0x0314, 0x0614, 0x0e14, 0x0f14,
     0x2714, 0x0714, 0x1714, 0x3714
 };
 
-static uint8_t vlc_tab_tone_level_idx_hi1_huffbits[20] = {
+static const uint8_t vlc_tab_tone_level_idx_hi1_huffbits[20] = {
     15, 4, 2, 1, 3, 5, 6, 7, 8, 10, 10, 11, 11, 12, 12, 12, 14, 14, 15, 14
 };
 
 /* values in this table range from -1..23; adjust retrieved value by -1 */
-static uint16_t vlc_tab_tone_level_idx_mid_huffcodes[24] = {
+static const uint16_t vlc_tab_tone_level_idx_mid_huffcodes[24] = {
     0x0fea, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000,
     0x0000, 0x0000, 0x0000, 0x0000, 0x03ea, 0x00ea, 0x002a, 0x001a,
     0x0006, 0x0001, 0x0000, 0x0002, 0x000a, 0x006a, 0x01ea, 0x07ea
 };
 
-static uint8_t vlc_tab_tone_level_idx_mid_huffbits[24] = {
+static const uint8_t vlc_tab_tone_level_idx_mid_huffbits[24] = {
     12, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 11, 9, 7, 5, 3, 1, 2, 4, 6, 8, 10, 12
 };
 
 /* values in this table range from -1..23; adjust retrieved value by -1 */
-static uint16_t vlc_tab_tone_level_idx_hi2_huffcodes[24] = {
+static const uint16_t vlc_tab_tone_level_idx_hi2_huffcodes[24] = {
     0x0664, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0064, 0x00e4,
     0x00a4, 0x0068, 0x0004, 0x0008, 0x0014, 0x0018, 0x0000, 0x0001,
     0x0002, 0x0003, 0x000c, 0x0028, 0x0024, 0x0164, 0x0000, 0x0264
 };
 
-static uint8_t vlc_tab_tone_level_idx_hi2_huffbits[24] = {
+static const uint8_t vlc_tab_tone_level_idx_hi2_huffbits[24] = {
     11, 0, 0, 0, 0, 0, 10, 8, 8, 7, 6, 6, 5, 5, 4, 2, 2, 2, 4, 7, 8, 9, 0, 11
 };
 
 /* values in this table range from -1..8; adjust retrieved value by -1 */
-static uint8_t vlc_tab_type30_huffcodes[9] = {
+static const uint8_t vlc_tab_type30_huffcodes[9] = {
     0x3c, 0x06, 0x00, 0x01, 0x03, 0x02, 0x04, 0x0c, 0x1c
 };
 
-static uint8_t vlc_tab_type30_huffbits[9] = {
+static const uint8_t vlc_tab_type30_huffbits[9] = {
     6, 3, 3, 2, 2, 3, 4, 5, 6
 };
 
 /* values in this table range from -1..9; adjust retrieved value by -1 */
-static uint8_t vlc_tab_type34_huffcodes[10] = {
+static const uint8_t vlc_tab_type34_huffcodes[10] = {
     0x18, 0x00, 0x01, 0x04, 0x05, 0x07, 0x03, 0x02, 0x06, 0x08
 };
 
-static uint8_t vlc_tab_type34_huffbits[10] = {
+static const uint8_t vlc_tab_type34_huffbits[10] = {
     5, 4, 3, 3, 3, 3, 3, 3, 3, 5
 };
 
 /* values in this table range from -1..22; adjust retrieved value by -1 */
-static uint16_t vlc_tab_fft_tone_offset_0_huffcodes[23] = {
+static const uint16_t vlc_tab_fft_tone_offset_0_huffcodes[23] = {
     0x038e, 0x0001, 0x0000, 0x0022, 0x000a, 0x0006, 0x0012, 0x0002,
     0x001e, 0x003e, 0x0056, 0x0016, 0x000e, 0x0032, 0x0072, 0x0042,
     0x008e, 0x004e, 0x00f2, 0x002e, 0x0036, 0x00c2, 0x018e
 };
 
-static uint8_t vlc_tab_fft_tone_offset_0_huffbits[23] = {
+static const uint8_t vlc_tab_fft_tone_offset_0_huffbits[23] = {
     10, 1, 2, 6, 4, 5, 6, 7, 6, 6, 7, 7, 8, 7, 8, 8, 9, 7, 8, 6, 6, 8, 10
 };
 
 /* values in this table range from -1..27; adjust retrieved value by -1 */
-static uint16_t vlc_tab_fft_tone_offset_1_huffcodes[28] = {
+static const uint16_t vlc_tab_fft_tone_offset_1_huffcodes[28] = {
     0x07a4, 0x0001, 0x0020, 0x0012, 0x001c, 0x0008, 0x0006, 0x0010,
     0x0000, 0x0014, 0x0004, 0x0032, 0x0070, 0x000c, 0x0002, 0x003a,
     0x001a, 0x002c, 0x002a, 0x0022, 0x0024, 0x000a, 0x0064, 0x0030,
     0x0062, 0x00a4, 0x01a4, 0x03a4
 };
 
-static uint8_t vlc_tab_fft_tone_offset_1_huffbits[28] = {
+static const uint8_t vlc_tab_fft_tone_offset_1_huffbits[28] = {
     11, 1, 6, 6, 5, 4, 3, 6, 6, 5, 6, 6, 7, 6, 6, 6,
     6, 6, 6, 7, 8, 6, 7, 7, 7, 9, 10, 11
 };
 
 /* values in this table range from -1..31; adjust retrieved value by -1 */
-static uint16_t vlc_tab_fft_tone_offset_2_huffcodes[32] = {
+static const uint16_t vlc_tab_fft_tone_offset_2_huffcodes[32] = {
     0x1760, 0x0001, 0x0000, 0x0082, 0x000c, 0x0006, 0x0003, 0x0007,
     0x0008, 0x0004, 0x0010, 0x0012, 0x0022, 0x001a, 0x0000, 0x0020,
     0x000a, 0x0040, 0x004a, 0x006a, 0x002a, 0x0042, 0x0002, 0x0060,
     0x00aa, 0x00e0, 0x00c2, 0x01c2, 0x0160, 0x0360, 0x0760, 0x0f60
 };
 
-static uint8_t vlc_tab_fft_tone_offset_2_huffbits[32] = {
+static const uint8_t vlc_tab_fft_tone_offset_2_huffbits[32] = {
     13, 2, 0, 8, 4, 3, 3, 3, 4, 4, 5, 5, 6, 5, 7, 7,
     7, 7, 7, 7, 8, 8, 8, 9, 8, 8, 9, 9, 10, 11, 13, 12
 };
 
 /* values in this table range from -1..34; adjust retrieved value by -1 */
-static uint16_t vlc_tab_fft_tone_offset_3_huffcodes[35] = {
+static const uint16_t vlc_tab_fft_tone_offset_3_huffcodes[35] = {
     0x33ea, 0x0005, 0x0000, 0x000c, 0x0000, 0x0006, 0x0003, 0x0008,
     0x0002, 0x0001, 0x0004, 0x0007, 0x001a, 0x000f, 0x001c, 0x002c,
     0x000a, 0x001d, 0x002d, 0x002a, 0x000d, 0x004c, 0x008c, 0x006a,
@@ -163,14 +163,14 @@
     0x0bea, 0x03ea, 0x13ea
 };
 
-static uint8_t vlc_tab_fft_tone_offset_3_huffbits[35] = {
+static const uint8_t vlc_tab_fft_tone_offset_3_huffbits[35] = {
     14, 4, 0, 10, 4, 3, 3, 4, 4, 3, 4, 4, 5, 4, 5, 6,
     6, 5, 6, 7, 7, 7, 8, 8, 8, 8, 9, 10, 10, 10, 10, 11,
     12, 13, 14
 };
 
 /* values in this table range from -1..37; adjust retrieved value by -1 */
-static uint16_t vlc_tab_fft_tone_offset_4_huffcodes[38] = {
+static const uint16_t vlc_tab_fft_tone_offset_4_huffcodes[38] = {
     0x5282, 0x0016, 0x0000, 0x0136, 0x0004, 0x0000, 0x0007, 0x000a,
     0x000e, 0x0003, 0x0001, 0x000d, 0x0006, 0x0009, 0x0012, 0x0005,
     0x0025, 0x0022, 0x0015, 0x0002, 0x0076, 0x0035, 0x0042, 0x00c2,
@@ -178,7 +178,7 @@
     0x0a82, 0x0082, 0x0282, 0x1282, 0x3282, 0x2282
 };
 
-static uint8_t vlc_tab_fft_tone_offset_4_huffbits[38] = {
+static const uint8_t vlc_tab_fft_tone_offset_4_huffbits[38] = {
     15, 6, 0, 9, 3, 3, 3, 4, 4, 3, 4, 4, 5, 4, 5, 6,
     6, 6, 6, 8, 7, 6, 8, 9, 9, 8, 9, 10, 11, 10, 11, 12,
     12, 12, 14, 15, 14, 14
@@ -187,44 +187,44 @@
 /** FFT TABLES **/
 
 /* values in this table range from -1..27; adjust retrieved value by -1 */
-static uint16_t fft_level_exp_alt_huffcodes[28] = {
+static const uint16_t fft_level_exp_alt_huffcodes[28] = {
     0x1ec6, 0x0006, 0x00c2, 0x0142, 0x0242, 0x0246, 0x00c6, 0x0046,
     0x0042, 0x0146, 0x00a2, 0x0062, 0x0026, 0x0016, 0x000e, 0x0005,
     0x0004, 0x0003, 0x0000, 0x0001, 0x000a, 0x0012, 0x0002, 0x0022,
     0x01c6, 0x02c6, 0x06c6, 0x0ec6
 };
 
-static uint8_t fft_level_exp_alt_huffbits[28] = {
+static const uint8_t fft_level_exp_alt_huffbits[28] = {
     13, 7, 8, 9, 10, 10, 10, 10, 10, 9, 8, 7, 6, 5, 4, 3,
     3, 2, 3, 3, 4, 5, 7, 8, 9, 11, 12, 13
 };
 
 /* values in this table range from -1..19; adjust retrieved value by -1 */
-static uint16_t fft_level_exp_huffcodes[20] = {
+static const uint16_t fft_level_exp_huffcodes[20] = {
     0x0f24, 0x0001, 0x0002, 0x0000, 0x0006, 0x0005, 0x0007, 0x000c,
     0x000b, 0x0014, 0x0013, 0x0004, 0x0003, 0x0023, 0x0064, 0x00a4,
     0x0024, 0x0124, 0x0324, 0x0724
 };
 
-static uint8_t fft_level_exp_huffbits[20] = {
+static const uint8_t fft_level_exp_huffbits[20] = {
     12, 3, 3, 3, 3, 3, 3, 4, 4, 5, 5, 6, 6, 6, 7, 8, 9, 10, 11, 12
 };
 
 /* values in this table range from -1..6; adjust retrieved value by -1 */
-static uint8_t fft_stereo_exp_huffcodes[7] = {
+static const uint8_t fft_stereo_exp_huffcodes[7] = {
     0x3e, 0x01, 0x00, 0x02, 0x06, 0x0e, 0x1e
 };
 
-static uint8_t fft_stereo_exp_huffbits[7] = {
+static const uint8_t fft_stereo_exp_huffbits[7] = {
     6, 1, 2, 3, 4, 5, 6
 };
 
 /* values in this table range from -1..8; adjust retrieved value by -1 */
-static uint8_t fft_stereo_phase_huffcodes[9] = {
+static const uint8_t fft_stereo_phase_huffcodes[9] = {
     0x35, 0x02, 0x00, 0x01, 0x0d, 0x15, 0x05, 0x09, 0x03
 };
 
-static uint8_t fft_stereo_phase_huffbits[9] = {
+static const uint8_t fft_stereo_phase_huffbits[9] = {
     6, 2, 2, 4, 4, 6, 5, 4, 2
 };
 
Index: libavcodec/utils.c
===================================================================
--- libavcodec/utils.c	(revision 5504)
+++ libavcodec/utils.c	(working copy)
@@ -450,7 +450,7 @@
 #define E AV_OPT_FLAG_ENCODING_PARAM
 #define D AV_OPT_FLAG_DECODING_PARAM
 
-static AVOption options[]={
+static const AVOption options[]={
 {"bit_rate", NULL, OFFSET(bit_rate), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|A|E},
 {"bit_rate_tolerance", NULL, OFFSET(bit_rate_tolerance), FF_OPT_TYPE_INT, DEFAULT, INT_MIN, INT_MAX, V|E},
 {"flags", NULL, OFFSET(flags), FF_OPT_TYPE_FLAGS, DEFAULT, INT_MIN, INT_MAX, V|A|E|D, "flags"},
Index: libavcodec/imgconvert.c
===================================================================
--- libavcodec/imgconvert.c	(revision 5504)
+++ libavcodec/imgconvert.c	(working copy)
@@ -63,7 +63,7 @@
 } PixFmtInfo;
 
 /* this table gives more information about formats */
-static PixFmtInfo pix_fmt_info[PIX_FMT_NB] = {
+static const PixFmtInfo pix_fmt_info[PIX_FMT_NB] = {
     /* YUV formats */
     [PIX_FMT_YUV420P] = {
         .name = "yuv420p",
@@ -266,7 +266,7 @@
                    int pix_fmt, int width, int height)
 {
     int size, w2, h2, size2;
-    PixFmtInfo *pinfo;
+    const PixFmtInfo *pinfo;
 
     if(avcodec_check_dimensions(NULL, width, height))
         goto fail;
@@ -359,7 +359,7 @@
 int avpicture_layout(const AVPicture* src, int pix_fmt, int width, int height,
                      unsigned char *dest, int dest_size)
 {
-    PixFmtInfo* pf = &pix_fmt_info[pix_fmt];
+    const PixFmtInfo* pf = &pix_fmt_info[pix_fmt];
     int i, j, w, h, data_planes;
     const unsigned char* s;
     int size = avpicture_get_size(pix_fmt, width, height);
@@ -592,7 +592,7 @@
               int pix_fmt, int width, int height)
 {
     int bwidth, bits, i;
-    PixFmtInfo *pf = &pix_fmt_info[pix_fmt];
+    const PixFmtInfo *pf = &pix_fmt_info[pix_fmt];
 
     pf = &pix_fmt_info[pix_fmt];
     switch(pf->pixel_type) {
@@ -1723,7 +1723,7 @@
 
    The other conversion functions are just optimisations for common cases.
 */
-static ConvertEntry convert_table[PIX_FMT_NB][PIX_FMT_NB] = {
+static const ConvertEntry convert_table[PIX_FMT_NB][PIX_FMT_NB] = {
     [PIX_FMT_YUV420P] = {
         [PIX_FMT_YUV422] = {
             .convert = yuv420p_to_yuv422,
@@ -1966,7 +1966,7 @@
 }
 
 /* return true if yuv planar */
-static inline int is_yuv_planar(PixFmtInfo *ps)
+static inline int is_yuv_planar(const PixFmtInfo *ps)
 {
     return (ps->color_type == FF_COLOR_YUV ||
             ps->color_type == FF_COLOR_YUV_JPEG) &&
@@ -2055,8 +2055,8 @@
 {
     static int inited;
     int i, ret, dst_width, dst_height, int_pix_fmt;
-    PixFmtInfo *src_pix, *dst_pix;
-    ConvertEntry *ce;
+    const PixFmtInfo *src_pix, *dst_pix;
+    const ConvertEntry *ce;
     AVPicture tmp1, *tmp = &tmp1;
 
     if (src_pix_fmt < 0 || src_pix_fmt >= PIX_FMT_NB ||
@@ -2323,7 +2323,7 @@
 int img_get_alpha_info(const AVPicture *src,
                        int pix_fmt, int width, int height)
 {
-    PixFmtInfo *pf = &pix_fmt_info[pix_fmt];
+    const PixFmtInfo *pf = &pix_fmt_info[pix_fmt];
     int ret;
 
     pf = &pix_fmt_info[pix_fmt];
Index: libavcodec/dpcm.c
===================================================================
--- libavcodec/dpcm.c	(revision 5504)
+++ libavcodec/dpcm.c	(working copy)
@@ -41,7 +41,7 @@
     int channels;
     short roq_square_array[256];
     long sample[2];//for SOL_DPCM
-    int *sol_table;//for SOL_DPCM
+    const int *sol_table;//for SOL_DPCM
 } DPCMContext;
 
 #define SATURATE_S16(x)  if (x < -32768) x = -32768; \
@@ -84,15 +84,15 @@
 
 };
 
-static int sol_table_old[16] =
+static const int sol_table_old[16] =
     { 0x0,  0x1,  0x2 , 0x3,  0x6,  0xA,  0xF, 0x15,
     -0x15, -0xF, -0xA, -0x6, -0x3, -0x2, -0x1, 0x0};
 
-static int sol_table_new[16] =
+static const int sol_table_new[16] =
     { 0x0,  0x1,  0x2,  0x3,  0x6,  0xA,  0xF,  0x15,
       0x0, -0x1, -0x2, -0x3, -0x6, -0xA, -0xF, -0x15};
 
-static int sol_table_16[128] = {
+static const int sol_table_16[128] = {
     0x000, 0x008, 0x010, 0x020, 0x030, 0x040, 0x050, 0x060, 0x070, 0x080,
     0x090, 0x0A0, 0x0B0, 0x0C0, 0x0D0, 0x0E0, 0x0F0, 0x100, 0x110, 0x120,
     0x130, 0x140, 0x150, 0x160, 0x170, 0x180, 0x190, 0x1A0, 0x1B0, 0x1C0,
Index: libavformat/nut.c
===================================================================
--- libavformat/nut.c	(revision 5504)
+++ libavformat/nut.c	(working copy)
@@ -1413,7 +1413,6 @@
 static int nut_read_close(AVFormatContext *s)
 {
     NUTContext *nut = s->priv_data;
-    int i;
 
     av_freep(&nut->stream);



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