old
/
legacy-imlib2
3
0
Fork 4
Code Issues 1 Pull Requests Projects Releases Wiki Activity

Y4M loader: Avoid use of sscanf() in frame rate parsing 

Input data is not necessarily nul-terminated.
Simplify frame rate parsing in the process.

Use of sscanf() should also be eliminated when compiling with debug -
some other day.

Based on patch by NRK.
This commit is contained in:
Kim Woelders 2024-01-01 15:51:13 +01:00
parent 4109f54c4a
commit 06314730ff
1 changed files with 14 additions and 44 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
src/modules/loaders/loader_y4m.c
View File

@ -34,20 +34,9 @@ enum Y4mParseStatus {
Y4M_PARSE_UNSUPPORTED,
};
// values are (roughly) equal to the delay in microseconds
#define Y4M_PARSE_FPS_INVALID 0
#define Y4M_PARSE_FPS_OTHER -1
#define Y4M_PARSE_FPS_23_976 41708
#define Y4M_PARSE_FPS_24 41667
#define Y4M_PARSE_FPS_25 40000
#define Y4M_PARSE_FPS_29_97 33367
#define Y4M_PARSE_FPS_30 33333
#define Y4M_PARSE_FPS_60 16667
#define Y4M_PARSE_FPS_1 1000000
typedef struct {
ptrdiff_t w, h;
int32_t fps;
ptrdiff_t fps_num, fps_den;
enum {
Y4M_PARSE_CS_420, /* default picked from ffmpeg */
Y4M_PARSE_CS_420JPEG,
@ -123,7 +112,7 @@ y4m__match(const char *match, ptrdiff_t mlen,
static enum Y4mParseStatus
y4m__parse_params(Y4mParse * res, const uint8_t ** start, const uint8_t * end)
{
const uint8_t *p = *start;
const uint8_t *p = *start, *pp;
for (;;)
{
@ -135,10 +124,10 @@ y4m__parse_params(Y4mParse * res, const uint8_t ** start, const uint8_t * end)
break;
case '\n':
*start = p;
if (res->w < 0 || res->h < 0 || res->fps == Y4M_PARSE_FPS_INVALID)
if (res->w <= 0 || res->h <= 0 ||
res->fps_num <= 0 || res->fps_den <= 0)
return Y4M_PARSE_CORRUPTED;
return Y4M_PARSE_OK;
break;
case 'W':
if (!y4m__int(&res->w, &p, end))
return Y4M_PARSE_CORRUPTED;
@ -148,36 +137,17 @@ y4m__parse_params(Y4mParse * res, const uint8_t ** start, const uint8_t * end)
return Y4M_PARSE_CORRUPTED;
break;
case 'F':
if (y4m__match("30:1", 4, &p, end))
res->fps = Y4M_PARSE_FPS_30;
else if (y4m__match("24:1", 4, &p, end))
res->fps = Y4M_PARSE_FPS_24;
else if (y4m__match("25:1", 4, &p, end))
res->fps = Y4M_PARSE_FPS_25;
else if (y4m__match("30000:1001", 10, &p, end))
res->fps = Y4M_PARSE_FPS_29_97;
else if (y4m__match("24000:1001", 10, &p, end))
res->fps = Y4M_PARSE_FPS_23_976;
else if (y4m__match("60:1", 4, &p, end))
res->fps = Y4M_PARSE_FPS_60;
else {
int rate_num;
int rate_den;
int nlen;
if (sscanf((const char *)p, "%i:%i%n", &rate_num, &rate_den, &nlen) < 2) {
return Y4M_PARSE_CORRUPTED;
}
p += nlen;
if (rate_num == rate_den) {
res->fps = Y4M_PARSE_FPS_1;
} else {
pp = p;
if (!y4m__int(&res->fps_num, &p, end) ||
!y4m__match(":", 1, &p, end) ||
!y4m__int(&res->fps_den, &p, end))
{
#if IMLIB2_DEBUG
char str[1024];
sscanf((const char *)(p-1), "%s", str);
D("%s: unknown frame rate: '%s'\n", __func__, str);
char str[1024];
sscanf((const char *)(pp-1), "%s", str);
D("%s: unknown frame rate: '%s'\n", __func__, str);
#endif
res->fps = Y4M_PARSE_FPS_OTHER;
}
return Y4M_PARSE_CORRUPTED;
}
break;
case 'I':
@ -439,7 +409,7 @@ _load(ImlibImage * im, int load_data)
{
pf->canvas_w = im->w;
pf->canvas_h = im->h;
pf->frame_delay = y4m.fps / 1000;
pf->frame_delay = (1000 * y4m.fps_den) / y4m.fps_num;
}
if (!load_data)