From 96e04dd8cf38ed0473e3ceebb0d77b95e38e569c Mon Sep 17 00:00:00 2001
From: Chema Gonzalez <chemag@meta.com>
Date: Wed, 27 Dec 2023 15:17:54 -0800
Subject: [PATCH] Y4M loader: add error messages on parsing errors

Tested:

Image with 420p10 color space.

Before:
```
$ IMLIB2_DEBUG=31:0 imlib2_view out.y4m
...
LOAD: __imlib_FindBestLoader: fmt='y4m': /usr/local/lib/imlib2/loaders/y4m.so
IMG : __imlib_LoadImageWrapper: fmt='y4m' file='out.y4m'(out.y4m) frame=1, imm=1
IMG : __imlib_LoadImageWrapper: y4m : out.y4m: Elapsed time: 0.010 ms
...
```

After:
```
$ IMLIB2_DEBUG=31:0 imlib2_view out.y4m
...
LOAD: __imlib_FindBestLoader: fmt='y4m': /usr/local/lib/imlib2/loaders/y4m.so
IMG : __imlib_LoadImageWrapper: fmt='y4m' file='out.y4m'(out.y4m) frame=1, imm=1
LDR-y4m: y4m__parse_params: unknown C: 'C420p10'
IMG : __imlib_LoadImageWrapper: y4m : out.y4m: Elapsed time: 0.010 ms
...
```
---
 src/modules/loaders/loader_y4m.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/modules/loaders/loader_y4m.c b/src/modules/loaders/loader_y4m.c
index 336f1f9..5612b42 100644
--- a/src/modules/loaders/loader_y4m.c
+++ b/src/modules/loaders/loader_y4m.c
@@ -171,6 +171,9 @@ y4m__parse_params(Y4mParse * res, const uint8_t ** start, const uint8_t * end)
                 if (rate_num == rate_den) {
                     res->fps = Y4M_PARSE_FPS_1;
                 } else {
+                    char str[1024];
+                    sscanf((char *)(p-1), "%s", (char *)&str);
+                    D("%s: unknown frame rate: '%s'\n", __func__, str);
                     res->fps = Y4M_PARSE_FPS_OTHER;
                 }
              }
@@ -184,8 +187,12 @@ y4m__parse_params(Y4mParse * res, const uint8_t ** start, const uint8_t * end)
                 res->interlacing = Y4M_PARSE_IL_BOTTOM;
              else if (y4m__match("m", 1, &p, end))
                 res->interlacing = Y4M_PARSE_IL_MIXED;
-             else
+             else {
+               char str[1024];
+               sscanf((char *)(p-1), "%s", (char *)&str);
+               D("%s: unknown interlace type: '%s'\n", __func__, str);
                 return Y4M_PARSE_CORRUPTED;
+             }
              break;
           case 'C':
              if (y4m__match("mono", 4, &p, end))
@@ -202,8 +209,12 @@ y4m__parse_params(Y4mParse * res, const uint8_t ** start, const uint8_t * end)
                 res->colour_space = Y4M_PARSE_CS_422;
              else if (y4m__match("444 ", 4, &p, end))
                 res->colour_space = Y4M_PARSE_CS_444;
-             else
+             else {
+                char str[1024];
+                sscanf((char *)(p-1), "%s", (char *)&str);
+                D("%s: unknown color type: '%s'\n", __func__, str);
                 return Y4M_PARSE_CORRUPTED;
+             }
              break;
           case 'A':
              if (y4m__match("0:0", 3, &p, end))