[FFmpeg-devel] [PATCH v2] Replace arrays of pointers to strings by arrays of strings
Andreas Rheinhardt
andreas.rheinhardt at gmail.com
Wed Jan 6 10:17:02 EET 2021
When the difference of the longest size and the average size of
collection of strings is smaller than the size of a pointer, it makes
sense to store the strings directly in an array instead of using an
array of pointers to strings (unless doing so precludes deduplicating
strings); doing so also avoids relocations. This requirement is
fulfilled for several arrays of pointers to strings that are changed in
this commit.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
Now used sizeof("longest string") for the array element size.
I'd still like to know whether I can simply work under the assumption
that pointers are 64bit when estimating whether other patches of this
kind are worth it (some changes that are worth it in 64bit could
actually be counterproductive size-wise for 32bit systems; but given
that these patches avoid relocations, overestimating sizeof(char*)
seems actually more accurate).
libavcodec/ccaption_dec.c | 4 ++--
libavcodec/vaapi_encode.c | 2 +-
libavfilter/af_hdcd.c | 2 +-
libavfilter/f_perms.c | 4 ++--
libavformat/iff.c | 4 ++--
libavformat/matroskadec.c | 2 +-
libavformat/sdp.c | 2 +-
libavutil/parseutils.c | 2 +-
8 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
index a208e19b95..0198158c38 100644
--- a/libavcodec/ccaption_dec.c
+++ b/libavcodec/ccaption_dec.c
@@ -66,7 +66,7 @@ enum cc_charset {
CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH,
};
-static const char *charset_overrides[4][128] =
+static const char charset_overrides[4][128][sizeof("\u266a")] =
{
[CCSET_BASIC_AMERICAN] = {
[0x27] = "\u2019",
@@ -575,7 +575,7 @@ static int capture_screen(CCaptionSubContext *ctx)
prev_color = color[j];
prev_bg_color = bg[j];
override = charset_overrides[(int)charset[j]][(int)row[j]];
- if (override) {
+ if (override[0]) {
av_bprintf(&ctx->buffer[bidx], "%s%s%s%s%s", e_tag, s_tag, c_tag, b_tag, override);
seen_char = 1;
} else if (row[j] == ' ' && !seen_char) {
diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
index 518e5b2c00..d643046b5d 100644
--- a/libavcodec/vaapi_encode.c
+++ b/libavcodec/vaapi_encode.c
@@ -33,7 +33,7 @@ const AVCodecHWConfigInternal *const ff_vaapi_encode_hw_configs[] = {
NULL,
};
-static const char * const picture_type_name[] = { "IDR", "I", "P", "B" };
+static const char picture_type_name[][sizeof("IDR")] = { "IDR", "I", "P", "B" };
static int vaapi_encode_make_packed_header(AVCodecContext *avctx,
VAAPIEncodePicture *pic,
diff --git a/libavfilter/af_hdcd.c b/libavfilter/af_hdcd.c
index 251d03229a..fc281a4620 100644
--- a/libavfilter/af_hdcd.c
+++ b/libavfilter/af_hdcd.c
@@ -900,7 +900,7 @@ typedef enum {
HDCD_PVER_MIX = 3, /**< Packets of type A and B discovered, most likely an encoding error */
} hdcd_pf;
-static const char * const pf_str[] = {
+static const char pf_str[][sizeof("A+B")] = {
"?", "A", "B", "A+B"
};
diff --git a/libavfilter/f_perms.c b/libavfilter/f_perms.c
index d984e5b150..ae4264038f 100644
--- a/libavfilter/f_perms.c
+++ b/libavfilter/f_perms.c
@@ -72,7 +72,7 @@ static av_cold int init(AVFilterContext *ctx)
}
enum perm { RO, RW };
-static const char * const perm_str[2] = { "RO", "RW" };
+static const char perm_str[] = { 'O', 'W' };
static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
{
@@ -91,7 +91,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
default: out_perm = in_perm; break;
}
- av_log(ctx, AV_LOG_VERBOSE, "%s -> %s%s\n",
+ av_log(ctx, AV_LOG_VERBOSE, "R%c -> R%c%s\n",
perm_str[in_perm], perm_str[out_perm],
in_perm == out_perm ? " (no-op)" : "");
diff --git a/libavformat/iff.c b/libavformat/iff.c
index 2dba121f6f..ad39e08649 100644
--- a/libavformat/iff.c
+++ b/libavformat/iff.c
@@ -199,13 +199,13 @@ static const uint64_t dsd_loudspeaker_config[] = {
AV_CH_LAYOUT_5POINT0, AV_CH_LAYOUT_5POINT1,
};
-static const char * dsd_source_comment[] = {
+static const char dsd_source_comment[][sizeof("analogue_source_comment")] = {
"dsd_source_comment",
"analogue_source_comment",
"pcm_source_comment",
};
-static const char * dsd_history_comment[] = {
+static const char dsd_history_comment[][sizeof("creating_machine")] = {
"general_remark",
"operator_name",
"creating_machine",
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 374831baa3..7b26face08 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1946,7 +1946,7 @@ static void matroska_parse_cues(MatroskaDemuxContext *matroska) {
static int matroska_aac_profile(char *codec_id)
{
- static const char *const aac_profiles[] = { "MAIN", "LC", "SSR" };
+ static const char aac_profiles[][sizeof("MAIN")] = { "MAIN", "LC", "SSR" };
int profile;
for (profile = 0; profile < FF_ARRAY_ELEMS(aac_profiles); profile++)
diff --git a/libavformat/sdp.c b/libavformat/sdp.c
index 95f3fbb876..69565e326d 100644
--- a/libavformat/sdp.c
+++ b/libavformat/sdp.c
@@ -230,7 +230,7 @@ static char *extradata2psets_hevc(AVCodecParameters *par)
int extradata_size = par->extradata_size;
uint8_t *tmpbuf = NULL;
int ps_pos[3] = { 0 };
- static const char * const ps_names[3] = { "vps", "sps", "pps" };
+ static const char ps_names[3][sizeof("vps")] = { "vps", "sps", "pps" };
int num_arrays, num_nalus;
int pos, i, j;
diff --git a/libavutil/parseutils.c b/libavutil/parseutils.c
index 167e822648..e43c249cee 100644
--- a/libavutil/parseutils.c
+++ b/libavutil/parseutils.c
@@ -140,7 +140,7 @@ static const VideoRateAbbr video_rate_abbrs[]= {
{ "ntsc-film", { 24000, 1001 } },
};
-static const char *months[12] = {
+static const char months[12][sizeof("september")] = {
"january", "february", "march", "april", "may", "june", "july", "august",
"september", "october", "november", "december"
};
--
2.25.1
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