Mercurial > SDL_sound_CoreAudio

comparison decoders/libmpg123/index.c @ 562:7e08477b0fc1

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
MP3 decoder upgrade work. Ripped out SMPEG and mpglib support, replaced it with "mpg123.c" and libmpg123. libmpg123 is a much better version of mpglib, so it should solve all the problems about MP3's not seeking, or most modern MP3's not playing at all, etc. Since you no longer have to make a tradeoff with SMPEG for features, and SMPEG is basically rotting, I removed it from the project. There is still work to be done with libmpg123...there are MMX, 3DNow, SSE, Altivec, etc decoders which we don't have enabled at the moment, and the build system could use some work to make this compile more cleanly, etc. Still: huge win.
author Ryan C. Gordon <icculus@icculus.org>
date Fri, 30 Jan 2009 02:44:47 -0500
parents
children
comparison
equal deleted inserted replaced
561:f2985e08589c 562:7e08477b0fc1
1 /*
2 index: frame index data structure and functions
3
4 copyright 2007-8 by the mpg123 project - free software under the terms of the LGPL 2.1
5 see COPYING and AUTHORS files in distribution or http://mpg123.org
6 initially written by Thomas Orgis
7 */
8
9 #include "index.h"
10 #include "debug.h"
11
12 /* The next expected frame offset, one step ahead. */
13 static off_t fi_next(struct frame_index *fi)
14 {
15 return (off_t)fi->fill*fi->step;
16 }
17
18 /* Shrink down the used index to the half.
19 Be careful with size = 1 ... there's no shrinking possible there. */
20 static void fi_shrink(struct frame_index *fi)
21 {
22 if(fi->fill < 2) return; /* Won't shrink below 1. */
23 else
24 { /* Double the step, half the fill. Should work as well for fill%2 = 1 */
25 size_t c;
26 debug2("shrink index with fill %lu and step %lu", (unsigned long)fi->fill, (unsigned long)fi->step);
27 fi->step *= 2;
28 fi->fill /= 2;
29 /* Move the data down. */
30 for(c = 0; c < fi->fill; ++c)
31 fi->data[c] = fi->data[2*c];
32 }
33
34 fi->next = fi_next(fi);
35 }
36
37 void fi_init(struct frame_index *fi)
38 {
39 fi->data = NULL;
40 fi->step = 1;
41 fi->fill = 0;
42 fi->size = 0;
43 fi->grow_size = 0;
44 fi->next = fi_next(fi);
45 }
46
47 void fi_exit(struct frame_index *fi)
48 {
49 debug2("fi_exit: %p and %lu", (void*)fi->data, (unsigned long)fi->size);
50 if(fi->size && fi->data != NULL) free(fi->data);
51
52 fi_init(fi); /* Be prepared for further fun, still. */
53 }
54
55 int fi_resize(struct frame_index *fi, size_t newsize)
56 {
57 off_t *newdata = NULL;
58 if(newsize == fi->size) return 0;
59
60 if(newsize > 0 && newsize < fi->size)
61 { /* When we reduce buffer size a bit, shrink stuff. */
62 while(fi->fill > newsize){ fi_shrink(fi); }
63 }
64
65 newdata = safe_realloc(fi->data, newsize*sizeof(off_t));
66 if(newsize == 0 || newdata != NULL)
67 {
68 fi->data = newdata;
69 fi->size = newsize;
70 if(fi->fill > fi->size) fi->fill = fi->size;
71
72 fi->next = fi_next(fi);
73 debug2("new index of size %lu at %p", (unsigned long)fi->size, (void*)fi->data);
74 return 0;
75 }
76 else
77 {
78 error("failed to resize index!");
79 return -1;
80 }
81 }
82
83 void fi_add(struct frame_index *fi, off_t pos)
84 {
85 debug3("wanting to add to fill %lu, step %lu, size %lu", (unsigned long)fi->fill, (unsigned long)fi->step, (unsigned long)fi->size);
86 if(fi->fill == fi->size)
87 { /* Index is full, we need to shrink... or grow. */
88 /* Store the current frame number to check later if we still want it. */
89 off_t framenum = fi->fill*fi->step;
90 /* If we want not / cannot grow, we shrink. */
91 if( !(fi->grow_size && fi_resize(fi, fi->size+fi->grow_size)==0) )
92 fi_shrink(fi);
93
94 /* Now check if we still want to add this frame (could be that not, because of changed step). */
95 if(fi->next != framenum) return;
96 }
97 /* When we are here, we want that frame. */
98 if(fi->fill < fi->size) /* safeguard for size=1, or just generally */
99 {
100 debug1("adding to index at %p", (void*)(fi->data+fi->fill));
101 fi->data[fi->fill] = pos;
102 ++fi->fill;
103 fi->next = fi_next(fi);
104 debug3("added pos %li to index with fill %lu and step %lu", (long) pos, (unsigned long)fi->fill, (unsigned long)fi->step);
105 }
106 }
107
108 void fi_reset(struct frame_index *fi)
109 {
110 debug1("reset with size %zu", fi->size);
111 fi->fill = 0;
112 fi->step = 1;
113 fi->next = fi_next(fi);
114 }