fixed bug #4410: respect original mp3 file offset.

libsdl-org · Jan 28, 2021 · ba82d21 · ba82d21
1 parent 9369412
commit ba82d21
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Showing 4 changed files with 25 additions and 16 deletions.
diff --git a/mp3utils.c b/mp3utils.c
@@ -20,6 +20,7 @@
 */
 
 #include "SDL_stdinc.h"
+#include "SDL_error.h"
 #include "SDL_rwops.h"
 
 #include "mp3utils.h"
@@ -28,6 +29,19 @@
 
 /*********************** SDL_RW WITH BOOKKEEPING ************************/
 
+int MP3_RWinit(struct mp3file_t *fil, SDL_RWops *src) {
+    fil->rw = src;
+    fil->start = SDL_RWtell(src);
+    fil->length = SDL_RWseek(src, 0, RW_SEEK_END) - fil->start;
+    fil->pos = 0;
+    if (fil->start < 0 || fil->length < 0) {
+        SDL_Error(SDL_EFSEEK);
+        return -1;
+    }
+    SDL_RWseek(src, fil->start, RW_SEEK_SET);
+    return 0;
+}
+
 int MP3_RWread(struct mp3file_t *fil, void *ptr, int size, int maxnum) {
     int remaining = fil->length - fil->pos;
     int ret;
@@ -54,7 +68,7 @@ int MP3_RWseek(struct mp3file_t *fil, int offset, int whence) {
     ret = SDL_RWseek(fil->rw, fil->start + offset, RW_SEEK_SET);
     if (ret < 0) return ret;
     fil->pos = offset;
-    return (fil->pos - fil->start);
+    return offset;
 }
 
 

diff --git a/mp3utils.h b/mp3utils.h
@@ -28,6 +28,7 @@ struct mp3file_t {
 };
 
 extern int mp3_skiptags(struct mp3file_t *fil);
+extern int MP3_RWinit(struct mp3file_t *fil, SDL_RWops *src);
 extern int MP3_RWread(struct mp3file_t *fil, void *ptr, int size, int maxnum);
 extern int MP3_RWseek(struct mp3file_t *fil, int offset, int whence);
 

diff --git a/music_mad.c b/music_mad.c
@@ -30,14 +30,12 @@ mad_openFileRW(SDL_RWops *rw, SDL_AudioSpec *mixer, int freerw)
 {
   mad_data *mp3_mad;
 
-  mp3_mad = (mad_data *)SDL_malloc(sizeof(mad_data));
+  mp3_mad = (mad_data *)SDL_calloc(1, sizeof(mad_data));
   if (mp3_mad) {
-	int pos = SDL_RWtell(rw);
-	mp3_mad->mp3file.rw = rw;
-	mp3_mad->mp3file.start = 0;
-	mp3_mad->mp3file.pos = 0;
-	mp3_mad->mp3file.length = SDL_RWseek(rw, 0, RW_SEEK_END);
-	SDL_RWseek(rw, pos, RW_SEEK_SET);
+	if (MP3_RWinit(&mp3_mad->mp3file, rw) < 0) {
+	    SDL_free(mp3_mad);
+	    return NULL;
+	}
 	if (mp3_skiptags(&mp3_mad->mp3file) < 0) {
 	    SDL_free(mp3_mad);
 	    Mix_SetError("music_mad: corrupt mp3 file (bad tags.)");

diff --git a/music_mpg.c b/music_mpg.c
@@ -103,27 +103,23 @@ mpg_data*
 mpg_new_rw(SDL_RWops *src, SDL_AudioSpec* mixer, int freesrc)
 {
     int fmt, result;
-    int pos;
     mpg_data* m = NULL;
 
     if (!Mix_Init(MIX_INIT_MP3)) {
         goto fail;
     }
 
-    m = (mpg_data*)SDL_malloc(sizeof(mpg_data));
+    m = (mpg_data*)SDL_calloc(1, sizeof(mpg_data));
     if (!m) {
         SDL_OutOfMemory();
         goto fail;
     }
 
-    SDL_memset(m, 0, sizeof(mpg_data));
-
-    m->mp3file.rw = src;
     m->freesrc = freesrc;
 
-    pos = SDL_RWtell(src);
-    m->mp3file.length = SDL_RWseek(src, 0, RW_SEEK_END);
-    SDL_RWseek(src, pos, RW_SEEK_SET);
+    if (MP3_RWinit(&m->mp3file, src) < 0) {
+        goto fail;
+    }
     if (mp3_skiptags(&m->mp3file) < 0) {
         Mix_SetError("music_mpg: corrupt mp3 file (bad tags.)");
         goto fail;