* [FFmpeg-devel] [PATCH] avcodec/ccaption_dec: Avoid relocations for strings
@ 2024-03-05 20:29 Andreas Rheinhardt
2024-03-05 20:56 ` Marth64
2024-03-07 8:13 ` Andreas Rheinhardt
0 siblings, 2 replies; 3+ messages in thread
From: Andreas Rheinhardt @ 2024-03-05 20:29 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Andreas Rheinhardt
The longest string here takes four bytes, so using an array
of pointers is wasteful even when ignoring the cost of relocations;
the lack of relocations also implies that this array
will now be put into .rodata and not into .data.rel.ro.
Static asserts are used to ensure that all strings are always
properly zero-terminated.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
Now using static asserts to address the main point of
criticism in https://patchwork.ffmpeg.org/project/ffmpeg/patch/20210106081702.2495510-1-andreas.rheinhardt@gmail.com/
libavcodec/ccaption_dec.c | 215 ++++++++++++++++++++------------------
1 file changed, 115 insertions(+), 100 deletions(-)
diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
index 95143e7e46..1550e4b253 100644
--- a/libavcodec/ccaption_dec.c
+++ b/libavcodec/ccaption_dec.c
@@ -67,108 +67,123 @@ enum cc_charset {
CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH,
};
-static const char *charset_overrides[4][128] =
+#define CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET) \
+ START_SET(CCSET_BASIC_AMERICAN) \
+ ENTRY(0x27, "\u2019") \
+ ENTRY(0x2a, "\u00e1") \
+ ENTRY(0x5c, "\u00e9") \
+ ENTRY(0x5e, "\u00ed") \
+ ENTRY(0x5f, "\u00f3") \
+ ENTRY(0x60, "\u00fa") \
+ ENTRY(0x7b, "\u00e7") \
+ ENTRY(0x7c, "\u00f7") \
+ ENTRY(0x7d, "\u00d1") \
+ ENTRY(0x7e, "\u00f1") \
+ ENTRY(0x7f, "\u2588") \
+ END_SET \
+ START_SET(CCSET_SPECIAL_AMERICAN) \
+ ENTRY(0x30, "\u00ae") \
+ ENTRY(0x31, "\u00b0") \
+ ENTRY(0x32, "\u00bd") \
+ ENTRY(0x33, "\u00bf") \
+ ENTRY(0x34, "\u2122") \
+ ENTRY(0x35, "\u00a2") \
+ ENTRY(0x36, "\u00a3") \
+ ENTRY(0x37, "\u266a") \
+ ENTRY(0x38, "\u00e0") \
+ ENTRY(0x39, "\u00A0") \
+ ENTRY(0x3a, "\u00e8") \
+ ENTRY(0x3b, "\u00e2") \
+ ENTRY(0x3c, "\u00ea") \
+ ENTRY(0x3d, "\u00ee") \
+ ENTRY(0x3e, "\u00f4") \
+ ENTRY(0x3f, "\u00fb") \
+ END_SET \
+ START_SET(CCSET_EXTENDED_SPANISH_FRENCH_MISC) \
+ ENTRY(0x20, "\u00c1") \
+ ENTRY(0x21, "\u00c9") \
+ ENTRY(0x22, "\u00d3") \
+ ENTRY(0x23, "\u00da") \
+ ENTRY(0x24, "\u00dc") \
+ ENTRY(0x25, "\u00fc") \
+ ENTRY(0x26, "\u00b4") \
+ ENTRY(0x27, "\u00a1") \
+ ENTRY(0x28, "*") \
+ ENTRY(0x29, "\u2018") \
+ ENTRY(0x2a, "-") \
+ ENTRY(0x2b, "\u00a9") \
+ ENTRY(0x2c, "\u2120") \
+ ENTRY(0x2d, "\u00b7") \
+ ENTRY(0x2e, "\u201c") \
+ ENTRY(0x2f, "\u201d") \
+ ENTRY(0x30, "\u00c0") \
+ ENTRY(0x31, "\u00c2") \
+ ENTRY(0x32, "\u00c7") \
+ ENTRY(0x33, "\u00c8") \
+ ENTRY(0x34, "\u00ca") \
+ ENTRY(0x35, "\u00cb") \
+ ENTRY(0x36, "\u00eb") \
+ ENTRY(0x37, "\u00ce") \
+ ENTRY(0x38, "\u00cf") \
+ ENTRY(0x39, "\u00ef") \
+ ENTRY(0x3a, "\u00d4") \
+ ENTRY(0x3b, "\u00d9") \
+ ENTRY(0x3c, "\u00f9") \
+ ENTRY(0x3d, "\u00db") \
+ ENTRY(0x3e, "\u00ab") \
+ ENTRY(0x3f, "\u00bb") \
+ END_SET \
+ START_SET(CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH) \
+ ENTRY(0x20, "\u00c3") \
+ ENTRY(0x21, "\u00e3") \
+ ENTRY(0x22, "\u00cd") \
+ ENTRY(0x23, "\u00cc") \
+ ENTRY(0x24, "\u00ec") \
+ ENTRY(0x25, "\u00d2") \
+ ENTRY(0x26, "\u00f2") \
+ ENTRY(0x27, "\u00d5") \
+ ENTRY(0x28, "\u00f5") \
+ ENTRY(0x29, "{") \
+ ENTRY(0x2a, "}") \
+ ENTRY(0x2b, "\\") \
+ ENTRY(0x2c, "^") \
+ ENTRY(0x2d, "_") \
+ ENTRY(0x2e, "|") \
+ ENTRY(0x2f, "~") \
+ ENTRY(0x30, "\u00c4") \
+ ENTRY(0x31, "\u00e4") \
+ ENTRY(0x32, "\u00d6") \
+ ENTRY(0x33, "\u00f6") \
+ ENTRY(0x34, "\u00df") \
+ ENTRY(0x35, "\u00a5") \
+ ENTRY(0x36, "\u00a4") \
+ ENTRY(0x37, "\u00a6") \
+ ENTRY(0x38, "\u00c5") \
+ ENTRY(0x39, "\u00e5") \
+ ENTRY(0x3a, "\u00d8") \
+ ENTRY(0x3b, "\u00f8") \
+ ENTRY(0x3c, "\u250c") \
+ ENTRY(0x3d, "\u2510") \
+ ENTRY(0x3e, "\u2514") \
+ ENTRY(0x3f, "\u2518") \
+ END_SET \
+
+static const char charset_overrides[4][128][sizeof("\u266a")] =
{
- [CCSET_BASIC_AMERICAN] = {
- [0x27] = "\u2019",
- [0x2a] = "\u00e1",
- [0x5c] = "\u00e9",
- [0x5e] = "\u00ed",
- [0x5f] = "\u00f3",
- [0x60] = "\u00fa",
- [0x7b] = "\u00e7",
- [0x7c] = "\u00f7",
- [0x7d] = "\u00d1",
- [0x7e] = "\u00f1",
- [0x7f] = "\u2588"
- },
- [CCSET_SPECIAL_AMERICAN] = {
- [0x30] = "\u00ae",
- [0x31] = "\u00b0",
- [0x32] = "\u00bd",
- [0x33] = "\u00bf",
- [0x34] = "\u2122",
- [0x35] = "\u00a2",
- [0x36] = "\u00a3",
- [0x37] = "\u266a",
- [0x38] = "\u00e0",
- [0x39] = "\u00A0",
- [0x3a] = "\u00e8",
- [0x3b] = "\u00e2",
- [0x3c] = "\u00ea",
- [0x3d] = "\u00ee",
- [0x3e] = "\u00f4",
- [0x3f] = "\u00fb",
- },
- [CCSET_EXTENDED_SPANISH_FRENCH_MISC] = {
- [0x20] = "\u00c1",
- [0x21] = "\u00c9",
- [0x22] = "\u00d3",
- [0x23] = "\u00da",
- [0x24] = "\u00dc",
- [0x25] = "\u00fc",
- [0x26] = "\u00b4",
- [0x27] = "\u00a1",
- [0x28] = "*",
- [0x29] = "\u2018",
- [0x2a] = "-",
- [0x2b] = "\u00a9",
- [0x2c] = "\u2120",
- [0x2d] = "\u00b7",
- [0x2e] = "\u201c",
- [0x2f] = "\u201d",
- [0x30] = "\u00c0",
- [0x31] = "\u00c2",
- [0x32] = "\u00c7",
- [0x33] = "\u00c8",
- [0x34] = "\u00ca",
- [0x35] = "\u00cb",
- [0x36] = "\u00eb",
- [0x37] = "\u00ce",
- [0x38] = "\u00cf",
- [0x39] = "\u00ef",
- [0x3a] = "\u00d4",
- [0x3b] = "\u00d9",
- [0x3c] = "\u00f9",
- [0x3d] = "\u00db",
- [0x3e] = "\u00ab",
- [0x3f] = "\u00bb",
- },
- [CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH] = {
- [0x20] = "\u00c3",
- [0x21] = "\u00e3",
- [0x22] = "\u00cd",
- [0x23] = "\u00cc",
- [0x24] = "\u00ec",
- [0x25] = "\u00d2",
- [0x26] = "\u00f2",
- [0x27] = "\u00d5",
- [0x28] = "\u00f5",
- [0x29] = "{",
- [0x2a] = "}",
- [0x2b] = "\\",
- [0x2c] = "^",
- [0x2d] = "_",
- [0x2e] = "|",
- [0x2f] = "~",
- [0x30] = "\u00c4",
- [0x31] = "\u00e4",
- [0x32] = "\u00d6",
- [0x33] = "\u00f6",
- [0x34] = "\u00df",
- [0x35] = "\u00a5",
- [0x36] = "\u00a4",
- [0x37] = "\u00a6",
- [0x38] = "\u00c5",
- [0x39] = "\u00e5",
- [0x3a] = "\u00d8",
- [0x3b] = "\u00f8",
- [0x3c] = "\u250c",
- [0x3d] = "\u2510",
- [0x3e] = "\u2514",
- [0x3f] = "\u2518",
+#define START_SET(IDX) \
+ [IDX] = {
+#define ENTRY(idx, string) \
+ [idx] = string,
+#define END_SET \
},
+ CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET)
};
+#define EMPTY_START(IDX)
+#define EMPTY_END
+#define ASSERT_ENTRY(IDX, str) \
+ _Static_assert(sizeof(str) <= sizeof(charset_overrides[0][0]), \
+ "'" str "' string takes too much space");
+CHARSET_OVERRIDE_LIST(EMPTY_START, ASSERT_ENTRY, EMPTY_END)
static const unsigned char bg_attribs[8] = // Color
{
@@ -571,7 +586,7 @@ 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) {
--
2.40.1
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [FFmpeg-devel] [PATCH] avcodec/ccaption_dec: Avoid relocations for strings
2024-03-05 20:29 [FFmpeg-devel] [PATCH] avcodec/ccaption_dec: Avoid relocations for strings Andreas Rheinhardt
@ 2024-03-05 20:56 ` Marth64
2024-03-07 8:13 ` Andreas Rheinhardt
1 sibling, 0 replies; 3+ messages in thread
From: Marth64 @ 2024-03-05 20:56 UTC (permalink / raw)
To: FFmpeg development discussions and patches; +Cc: Andreas Rheinhardt
I did a quick validation with ATSC, DVD, and SCTE sources. Results were as
expected.
On Tue, Mar 5, 2024 at 2:30 PM Andreas Rheinhardt <
andreas.rheinhardt@outlook.com> wrote:
> The longest string here takes four bytes, so using an array
> of pointers is wasteful even when ignoring the cost of relocations;
> the lack of relocations also implies that this array
> will now be put into .rodata and not into .data.rel.ro.
>
> Static asserts are used to ensure that all strings are always
> properly zero-terminated.
>
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
> ---
> Now using static asserts to address the main point of
> criticism in
> https://patchwork.ffmpeg.org/project/ffmpeg/patch/20210106081702.2495510-1-andreas.rheinhardt@gmail.com/
>
> libavcodec/ccaption_dec.c | 215 ++++++++++++++++++++------------------
> 1 file changed, 115 insertions(+), 100 deletions(-)
>
> diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
> index 95143e7e46..1550e4b253 100644
> --- a/libavcodec/ccaption_dec.c
> +++ b/libavcodec/ccaption_dec.c
> @@ -67,108 +67,123 @@ enum cc_charset {
> CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH,
> };
>
> -static const char *charset_overrides[4][128] =
> +#define CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET) \
> + START_SET(CCSET_BASIC_AMERICAN) \
> + ENTRY(0x27, "\u2019") \
> + ENTRY(0x2a, "\u00e1") \
> + ENTRY(0x5c, "\u00e9") \
> + ENTRY(0x5e, "\u00ed") \
> + ENTRY(0x5f, "\u00f3") \
> + ENTRY(0x60, "\u00fa") \
> + ENTRY(0x7b, "\u00e7") \
> + ENTRY(0x7c, "\u00f7") \
> + ENTRY(0x7d, "\u00d1") \
> + ENTRY(0x7e, "\u00f1") \
> + ENTRY(0x7f, "\u2588") \
> + END_SET \
> + START_SET(CCSET_SPECIAL_AMERICAN) \
> + ENTRY(0x30, "\u00ae") \
> + ENTRY(0x31, "\u00b0") \
> + ENTRY(0x32, "\u00bd") \
> + ENTRY(0x33, "\u00bf") \
> + ENTRY(0x34, "\u2122") \
> + ENTRY(0x35, "\u00a2") \
> + ENTRY(0x36, "\u00a3") \
> + ENTRY(0x37, "\u266a") \
> + ENTRY(0x38, "\u00e0") \
> + ENTRY(0x39, "\u00A0") \
> + ENTRY(0x3a, "\u00e8") \
> + ENTRY(0x3b, "\u00e2") \
> + ENTRY(0x3c, "\u00ea") \
> + ENTRY(0x3d, "\u00ee") \
> + ENTRY(0x3e, "\u00f4") \
> + ENTRY(0x3f, "\u00fb") \
> + END_SET \
> + START_SET(CCSET_EXTENDED_SPANISH_FRENCH_MISC) \
> + ENTRY(0x20, "\u00c1") \
> + ENTRY(0x21, "\u00c9") \
> + ENTRY(0x22, "\u00d3") \
> + ENTRY(0x23, "\u00da") \
> + ENTRY(0x24, "\u00dc") \
> + ENTRY(0x25, "\u00fc") \
> + ENTRY(0x26, "\u00b4") \
> + ENTRY(0x27, "\u00a1") \
> + ENTRY(0x28, "*") \
> + ENTRY(0x29, "\u2018") \
> + ENTRY(0x2a, "-") \
> + ENTRY(0x2b, "\u00a9") \
> + ENTRY(0x2c, "\u2120") \
> + ENTRY(0x2d, "\u00b7") \
> + ENTRY(0x2e, "\u201c") \
> + ENTRY(0x2f, "\u201d") \
> + ENTRY(0x30, "\u00c0") \
> + ENTRY(0x31, "\u00c2") \
> + ENTRY(0x32, "\u00c7") \
> + ENTRY(0x33, "\u00c8") \
> + ENTRY(0x34, "\u00ca") \
> + ENTRY(0x35, "\u00cb") \
> + ENTRY(0x36, "\u00eb") \
> + ENTRY(0x37, "\u00ce") \
> + ENTRY(0x38, "\u00cf") \
> + ENTRY(0x39, "\u00ef") \
> + ENTRY(0x3a, "\u00d4") \
> + ENTRY(0x3b, "\u00d9") \
> + ENTRY(0x3c, "\u00f9") \
> + ENTRY(0x3d, "\u00db") \
> + ENTRY(0x3e, "\u00ab") \
> + ENTRY(0x3f, "\u00bb") \
> + END_SET \
> + START_SET(CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH) \
> + ENTRY(0x20, "\u00c3") \
> + ENTRY(0x21, "\u00e3") \
> + ENTRY(0x22, "\u00cd") \
> + ENTRY(0x23, "\u00cc") \
> + ENTRY(0x24, "\u00ec") \
> + ENTRY(0x25, "\u00d2") \
> + ENTRY(0x26, "\u00f2") \
> + ENTRY(0x27, "\u00d5") \
> + ENTRY(0x28, "\u00f5") \
> + ENTRY(0x29, "{") \
> + ENTRY(0x2a, "}") \
> + ENTRY(0x2b, "\\") \
> + ENTRY(0x2c, "^") \
> + ENTRY(0x2d, "_") \
> + ENTRY(0x2e, "|") \
> + ENTRY(0x2f, "~") \
> + ENTRY(0x30, "\u00c4") \
> + ENTRY(0x31, "\u00e4") \
> + ENTRY(0x32, "\u00d6") \
> + ENTRY(0x33, "\u00f6") \
> + ENTRY(0x34, "\u00df") \
> + ENTRY(0x35, "\u00a5") \
> + ENTRY(0x36, "\u00a4") \
> + ENTRY(0x37, "\u00a6") \
> + ENTRY(0x38, "\u00c5") \
> + ENTRY(0x39, "\u00e5") \
> + ENTRY(0x3a, "\u00d8") \
> + ENTRY(0x3b, "\u00f8") \
> + ENTRY(0x3c, "\u250c") \
> + ENTRY(0x3d, "\u2510") \
> + ENTRY(0x3e, "\u2514") \
> + ENTRY(0x3f, "\u2518") \
> + END_SET \
> +
> +static const char charset_overrides[4][128][sizeof("\u266a")] =
> {
> - [CCSET_BASIC_AMERICAN] = {
> - [0x27] = "\u2019",
> - [0x2a] = "\u00e1",
> - [0x5c] = "\u00e9",
> - [0x5e] = "\u00ed",
> - [0x5f] = "\u00f3",
> - [0x60] = "\u00fa",
> - [0x7b] = "\u00e7",
> - [0x7c] = "\u00f7",
> - [0x7d] = "\u00d1",
> - [0x7e] = "\u00f1",
> - [0x7f] = "\u2588"
> - },
> - [CCSET_SPECIAL_AMERICAN] = {
> - [0x30] = "\u00ae",
> - [0x31] = "\u00b0",
> - [0x32] = "\u00bd",
> - [0x33] = "\u00bf",
> - [0x34] = "\u2122",
> - [0x35] = "\u00a2",
> - [0x36] = "\u00a3",
> - [0x37] = "\u266a",
> - [0x38] = "\u00e0",
> - [0x39] = "\u00A0",
> - [0x3a] = "\u00e8",
> - [0x3b] = "\u00e2",
> - [0x3c] = "\u00ea",
> - [0x3d] = "\u00ee",
> - [0x3e] = "\u00f4",
> - [0x3f] = "\u00fb",
> - },
> - [CCSET_EXTENDED_SPANISH_FRENCH_MISC] = {
> - [0x20] = "\u00c1",
> - [0x21] = "\u00c9",
> - [0x22] = "\u00d3",
> - [0x23] = "\u00da",
> - [0x24] = "\u00dc",
> - [0x25] = "\u00fc",
> - [0x26] = "\u00b4",
> - [0x27] = "\u00a1",
> - [0x28] = "*",
> - [0x29] = "\u2018",
> - [0x2a] = "-",
> - [0x2b] = "\u00a9",
> - [0x2c] = "\u2120",
> - [0x2d] = "\u00b7",
> - [0x2e] = "\u201c",
> - [0x2f] = "\u201d",
> - [0x30] = "\u00c0",
> - [0x31] = "\u00c2",
> - [0x32] = "\u00c7",
> - [0x33] = "\u00c8",
> - [0x34] = "\u00ca",
> - [0x35] = "\u00cb",
> - [0x36] = "\u00eb",
> - [0x37] = "\u00ce",
> - [0x38] = "\u00cf",
> - [0x39] = "\u00ef",
> - [0x3a] = "\u00d4",
> - [0x3b] = "\u00d9",
> - [0x3c] = "\u00f9",
> - [0x3d] = "\u00db",
> - [0x3e] = "\u00ab",
> - [0x3f] = "\u00bb",
> - },
> - [CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH] = {
> - [0x20] = "\u00c3",
> - [0x21] = "\u00e3",
> - [0x22] = "\u00cd",
> - [0x23] = "\u00cc",
> - [0x24] = "\u00ec",
> - [0x25] = "\u00d2",
> - [0x26] = "\u00f2",
> - [0x27] = "\u00d5",
> - [0x28] = "\u00f5",
> - [0x29] = "{",
> - [0x2a] = "}",
> - [0x2b] = "\\",
> - [0x2c] = "^",
> - [0x2d] = "_",
> - [0x2e] = "|",
> - [0x2f] = "~",
> - [0x30] = "\u00c4",
> - [0x31] = "\u00e4",
> - [0x32] = "\u00d6",
> - [0x33] = "\u00f6",
> - [0x34] = "\u00df",
> - [0x35] = "\u00a5",
> - [0x36] = "\u00a4",
> - [0x37] = "\u00a6",
> - [0x38] = "\u00c5",
> - [0x39] = "\u00e5",
> - [0x3a] = "\u00d8",
> - [0x3b] = "\u00f8",
> - [0x3c] = "\u250c",
> - [0x3d] = "\u2510",
> - [0x3e] = "\u2514",
> - [0x3f] = "\u2518",
> +#define START_SET(IDX) \
> + [IDX] = {
> +#define ENTRY(idx, string) \
> + [idx] = string,
> +#define END_SET \
> },
> + CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET)
> };
> +#define EMPTY_START(IDX)
> +#define EMPTY_END
> +#define ASSERT_ENTRY(IDX, str) \
> + _Static_assert(sizeof(str) <= sizeof(charset_overrides[0][0]), \
> + "'" str "' string takes too much space");
> +CHARSET_OVERRIDE_LIST(EMPTY_START, ASSERT_ENTRY, EMPTY_END)
>
> static const unsigned char bg_attribs[8] = // Color
> {
> @@ -571,7 +586,7 @@ 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) {
> --
> 2.40.1
>
> _______________________________________________
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^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [FFmpeg-devel] [PATCH] avcodec/ccaption_dec: Avoid relocations for strings
2024-03-05 20:29 [FFmpeg-devel] [PATCH] avcodec/ccaption_dec: Avoid relocations for strings Andreas Rheinhardt
2024-03-05 20:56 ` Marth64
@ 2024-03-07 8:13 ` Andreas Rheinhardt
1 sibling, 0 replies; 3+ messages in thread
From: Andreas Rheinhardt @ 2024-03-07 8:13 UTC (permalink / raw)
To: ffmpeg-devel
Andreas Rheinhardt:
> The longest string here takes four bytes, so using an array
> of pointers is wasteful even when ignoring the cost of relocations;
> the lack of relocations also implies that this array
> will now be put into .rodata and not into .data.rel.ro.
>
> Static asserts are used to ensure that all strings are always
> properly zero-terminated.
>
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
> ---
> Now using static asserts to address the main point of
> criticism in https://patchwork.ffmpeg.org/project/ffmpeg/patch/20210106081702.2495510-1-andreas.rheinhardt@gmail.com/
>
> libavcodec/ccaption_dec.c | 215 ++++++++++++++++++++------------------
> 1 file changed, 115 insertions(+), 100 deletions(-)
>
> diff --git a/libavcodec/ccaption_dec.c b/libavcodec/ccaption_dec.c
> index 95143e7e46..1550e4b253 100644
> --- a/libavcodec/ccaption_dec.c
> +++ b/libavcodec/ccaption_dec.c
> @@ -67,108 +67,123 @@ enum cc_charset {
> CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH,
> };
>
> -static const char *charset_overrides[4][128] =
> +#define CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET) \
> + START_SET(CCSET_BASIC_AMERICAN) \
> + ENTRY(0x27, "\u2019") \
> + ENTRY(0x2a, "\u00e1") \
> + ENTRY(0x5c, "\u00e9") \
> + ENTRY(0x5e, "\u00ed") \
> + ENTRY(0x5f, "\u00f3") \
> + ENTRY(0x60, "\u00fa") \
> + ENTRY(0x7b, "\u00e7") \
> + ENTRY(0x7c, "\u00f7") \
> + ENTRY(0x7d, "\u00d1") \
> + ENTRY(0x7e, "\u00f1") \
> + ENTRY(0x7f, "\u2588") \
> + END_SET \
> + START_SET(CCSET_SPECIAL_AMERICAN) \
> + ENTRY(0x30, "\u00ae") \
> + ENTRY(0x31, "\u00b0") \
> + ENTRY(0x32, "\u00bd") \
> + ENTRY(0x33, "\u00bf") \
> + ENTRY(0x34, "\u2122") \
> + ENTRY(0x35, "\u00a2") \
> + ENTRY(0x36, "\u00a3") \
> + ENTRY(0x37, "\u266a") \
> + ENTRY(0x38, "\u00e0") \
> + ENTRY(0x39, "\u00A0") \
> + ENTRY(0x3a, "\u00e8") \
> + ENTRY(0x3b, "\u00e2") \
> + ENTRY(0x3c, "\u00ea") \
> + ENTRY(0x3d, "\u00ee") \
> + ENTRY(0x3e, "\u00f4") \
> + ENTRY(0x3f, "\u00fb") \
> + END_SET \
> + START_SET(CCSET_EXTENDED_SPANISH_FRENCH_MISC) \
> + ENTRY(0x20, "\u00c1") \
> + ENTRY(0x21, "\u00c9") \
> + ENTRY(0x22, "\u00d3") \
> + ENTRY(0x23, "\u00da") \
> + ENTRY(0x24, "\u00dc") \
> + ENTRY(0x25, "\u00fc") \
> + ENTRY(0x26, "\u00b4") \
> + ENTRY(0x27, "\u00a1") \
> + ENTRY(0x28, "*") \
> + ENTRY(0x29, "\u2018") \
> + ENTRY(0x2a, "-") \
> + ENTRY(0x2b, "\u00a9") \
> + ENTRY(0x2c, "\u2120") \
> + ENTRY(0x2d, "\u00b7") \
> + ENTRY(0x2e, "\u201c") \
> + ENTRY(0x2f, "\u201d") \
> + ENTRY(0x30, "\u00c0") \
> + ENTRY(0x31, "\u00c2") \
> + ENTRY(0x32, "\u00c7") \
> + ENTRY(0x33, "\u00c8") \
> + ENTRY(0x34, "\u00ca") \
> + ENTRY(0x35, "\u00cb") \
> + ENTRY(0x36, "\u00eb") \
> + ENTRY(0x37, "\u00ce") \
> + ENTRY(0x38, "\u00cf") \
> + ENTRY(0x39, "\u00ef") \
> + ENTRY(0x3a, "\u00d4") \
> + ENTRY(0x3b, "\u00d9") \
> + ENTRY(0x3c, "\u00f9") \
> + ENTRY(0x3d, "\u00db") \
> + ENTRY(0x3e, "\u00ab") \
> + ENTRY(0x3f, "\u00bb") \
> + END_SET \
> + START_SET(CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH) \
> + ENTRY(0x20, "\u00c3") \
> + ENTRY(0x21, "\u00e3") \
> + ENTRY(0x22, "\u00cd") \
> + ENTRY(0x23, "\u00cc") \
> + ENTRY(0x24, "\u00ec") \
> + ENTRY(0x25, "\u00d2") \
> + ENTRY(0x26, "\u00f2") \
> + ENTRY(0x27, "\u00d5") \
> + ENTRY(0x28, "\u00f5") \
> + ENTRY(0x29, "{") \
> + ENTRY(0x2a, "}") \
> + ENTRY(0x2b, "\\") \
> + ENTRY(0x2c, "^") \
> + ENTRY(0x2d, "_") \
> + ENTRY(0x2e, "|") \
> + ENTRY(0x2f, "~") \
> + ENTRY(0x30, "\u00c4") \
> + ENTRY(0x31, "\u00e4") \
> + ENTRY(0x32, "\u00d6") \
> + ENTRY(0x33, "\u00f6") \
> + ENTRY(0x34, "\u00df") \
> + ENTRY(0x35, "\u00a5") \
> + ENTRY(0x36, "\u00a4") \
> + ENTRY(0x37, "\u00a6") \
> + ENTRY(0x38, "\u00c5") \
> + ENTRY(0x39, "\u00e5") \
> + ENTRY(0x3a, "\u00d8") \
> + ENTRY(0x3b, "\u00f8") \
> + ENTRY(0x3c, "\u250c") \
> + ENTRY(0x3d, "\u2510") \
> + ENTRY(0x3e, "\u2514") \
> + ENTRY(0x3f, "\u2518") \
> + END_SET \
> +
> +static const char charset_overrides[4][128][sizeof("\u266a")] =
> {
> - [CCSET_BASIC_AMERICAN] = {
> - [0x27] = "\u2019",
> - [0x2a] = "\u00e1",
> - [0x5c] = "\u00e9",
> - [0x5e] = "\u00ed",
> - [0x5f] = "\u00f3",
> - [0x60] = "\u00fa",
> - [0x7b] = "\u00e7",
> - [0x7c] = "\u00f7",
> - [0x7d] = "\u00d1",
> - [0x7e] = "\u00f1",
> - [0x7f] = "\u2588"
> - },
> - [CCSET_SPECIAL_AMERICAN] = {
> - [0x30] = "\u00ae",
> - [0x31] = "\u00b0",
> - [0x32] = "\u00bd",
> - [0x33] = "\u00bf",
> - [0x34] = "\u2122",
> - [0x35] = "\u00a2",
> - [0x36] = "\u00a3",
> - [0x37] = "\u266a",
> - [0x38] = "\u00e0",
> - [0x39] = "\u00A0",
> - [0x3a] = "\u00e8",
> - [0x3b] = "\u00e2",
> - [0x3c] = "\u00ea",
> - [0x3d] = "\u00ee",
> - [0x3e] = "\u00f4",
> - [0x3f] = "\u00fb",
> - },
> - [CCSET_EXTENDED_SPANISH_FRENCH_MISC] = {
> - [0x20] = "\u00c1",
> - [0x21] = "\u00c9",
> - [0x22] = "\u00d3",
> - [0x23] = "\u00da",
> - [0x24] = "\u00dc",
> - [0x25] = "\u00fc",
> - [0x26] = "\u00b4",
> - [0x27] = "\u00a1",
> - [0x28] = "*",
> - [0x29] = "\u2018",
> - [0x2a] = "-",
> - [0x2b] = "\u00a9",
> - [0x2c] = "\u2120",
> - [0x2d] = "\u00b7",
> - [0x2e] = "\u201c",
> - [0x2f] = "\u201d",
> - [0x30] = "\u00c0",
> - [0x31] = "\u00c2",
> - [0x32] = "\u00c7",
> - [0x33] = "\u00c8",
> - [0x34] = "\u00ca",
> - [0x35] = "\u00cb",
> - [0x36] = "\u00eb",
> - [0x37] = "\u00ce",
> - [0x38] = "\u00cf",
> - [0x39] = "\u00ef",
> - [0x3a] = "\u00d4",
> - [0x3b] = "\u00d9",
> - [0x3c] = "\u00f9",
> - [0x3d] = "\u00db",
> - [0x3e] = "\u00ab",
> - [0x3f] = "\u00bb",
> - },
> - [CCSET_EXTENDED_PORTUGUESE_GERMAN_DANISH] = {
> - [0x20] = "\u00c3",
> - [0x21] = "\u00e3",
> - [0x22] = "\u00cd",
> - [0x23] = "\u00cc",
> - [0x24] = "\u00ec",
> - [0x25] = "\u00d2",
> - [0x26] = "\u00f2",
> - [0x27] = "\u00d5",
> - [0x28] = "\u00f5",
> - [0x29] = "{",
> - [0x2a] = "}",
> - [0x2b] = "\\",
> - [0x2c] = "^",
> - [0x2d] = "_",
> - [0x2e] = "|",
> - [0x2f] = "~",
> - [0x30] = "\u00c4",
> - [0x31] = "\u00e4",
> - [0x32] = "\u00d6",
> - [0x33] = "\u00f6",
> - [0x34] = "\u00df",
> - [0x35] = "\u00a5",
> - [0x36] = "\u00a4",
> - [0x37] = "\u00a6",
> - [0x38] = "\u00c5",
> - [0x39] = "\u00e5",
> - [0x3a] = "\u00d8",
> - [0x3b] = "\u00f8",
> - [0x3c] = "\u250c",
> - [0x3d] = "\u2510",
> - [0x3e] = "\u2514",
> - [0x3f] = "\u2518",
> +#define START_SET(IDX) \
> + [IDX] = {
> +#define ENTRY(idx, string) \
> + [idx] = string,
> +#define END_SET \
> },
> + CHARSET_OVERRIDE_LIST(START_SET, ENTRY, END_SET)
> };
> +#define EMPTY_START(IDX)
> +#define EMPTY_END
> +#define ASSERT_ENTRY(IDX, str) \
> + _Static_assert(sizeof(str) <= sizeof(charset_overrides[0][0]), \
> + "'" str "' string takes too much space");
> +CHARSET_OVERRIDE_LIST(EMPTY_START, ASSERT_ENTRY, EMPTY_END)
>
> static const unsigned char bg_attribs[8] = // Color
> {
> @@ -571,7 +586,7 @@ 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) {
Will apply this patch tomorrow unless there are objections.
- Andreas
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2024-03-05 20:29 [FFmpeg-devel] [PATCH] avcodec/ccaption_dec: Avoid relocations for strings Andreas Rheinhardt
2024-03-05 20:56 ` Marth64
2024-03-07 8:13 ` Andreas Rheinhardt
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