1 /* GStreamer Wavpack plugin
2 * Copyright (c) 2006 Sebastian Dröge <slomo@circular-chaos.org>
3 *
4 * gstwavpackstreamreader.c: stream reader used for decoding
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
15 *
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
19 * Boston, MA 02110-1301, USA.
20 */
21
22 #include <string.h>
23 #include <math.h>
24 #include <gst/gst.h>
25
26 #include "gstwavpackstreamreader.h"
27
28 GST_DEBUG_CATEGORY_EXTERN (wavpack_debug);
29 #define GST_CAT_DEFAULT wavpack_debug
30
31 static int32_t
gst_wavpack_stream_reader_read_bytes(void * id,void * data,int32_t bcount)32 gst_wavpack_stream_reader_read_bytes (void *id, void *data, int32_t bcount)
33 {
34 read_id *rid = (read_id *) id;
35 uint32_t left = rid->length - rid->position;
36 uint32_t to_read = MIN (left, bcount);
37
38 GST_DEBUG ("Trying to read %d of %d bytes from position %d", bcount,
39 rid->length, rid->position);
40
41 if (to_read > 0) {
42 memmove (data, rid->buffer + rid->position, to_read);
43 rid->position += to_read;
44 return to_read;
45 } else {
46 GST_WARNING ("Couldn't read %d bytes", bcount);
47 return 0;
48 }
49 }
50
51 static uint32_t
gst_wavpack_stream_reader_get_pos(void * id)52 gst_wavpack_stream_reader_get_pos (void *id)
53 {
54 GST_DEBUG ("Returning position %d", ((read_id *) id)->position);
55 return ((read_id *) id)->position;
56 }
57
58 static int
gst_wavpack_stream_reader_set_pos_abs(void * id,uint32_t pos)59 gst_wavpack_stream_reader_set_pos_abs (void *id, uint32_t pos)
60 {
61 GST_WARNING ("Should not be called: tried to set absolute position to %d",
62 pos);
63 return -1;
64 }
65
66 static int
gst_wavpack_stream_reader_set_pos_rel(void * id,int32_t delta,int mode)67 gst_wavpack_stream_reader_set_pos_rel (void *id, int32_t delta, int mode)
68 {
69 GST_WARNING ("Should not be called: tried to set relative position to %d"
70 " with mode %d", delta, mode);
71 return -1;
72 }
73
74 static int
gst_wavpack_stream_reader_push_back_byte(void * id,int c)75 gst_wavpack_stream_reader_push_back_byte (void *id, int c)
76 {
77 read_id *rid = (read_id *) id;
78
79 GST_DEBUG ("Pushing back one byte: 0x%x", c);
80
81 if (rid->position == 0)
82 return rid->position;
83
84 rid->position -= 1;
85 return rid->position;
86 }
87
88 static uint32_t
gst_wavpack_stream_reader_get_length(void * id)89 gst_wavpack_stream_reader_get_length (void *id)
90 {
91 GST_DEBUG ("Returning length %d", ((read_id *) id)->length);
92
93 return ((read_id *) id)->length;
94 }
95
96 static int
gst_wavpack_stream_reader_can_seek(void * id)97 gst_wavpack_stream_reader_can_seek (void *id)
98 {
99 GST_DEBUG ("Can't seek");
100 return FALSE;
101 }
102
103 static int32_t
gst_wavpack_stream_reader_write_bytes(void * id,void * data,int32_t bcount)104 gst_wavpack_stream_reader_write_bytes (void *id, void *data, int32_t bcount)
105 {
106 GST_WARNING ("Should not be called, tried to write %d bytes", bcount);
107 return 0;
108 }
109
110 WavpackStreamReader *
gst_wavpack_stream_reader_new(void)111 gst_wavpack_stream_reader_new (void)
112 {
113 WavpackStreamReader *stream_reader =
114 (WavpackStreamReader *) g_malloc0 (sizeof (WavpackStreamReader));
115 stream_reader->read_bytes = gst_wavpack_stream_reader_read_bytes;
116 stream_reader->get_pos = gst_wavpack_stream_reader_get_pos;
117 stream_reader->set_pos_abs = gst_wavpack_stream_reader_set_pos_abs;
118 stream_reader->set_pos_rel = gst_wavpack_stream_reader_set_pos_rel;
119 stream_reader->push_back_byte = gst_wavpack_stream_reader_push_back_byte;
120 stream_reader->get_length = gst_wavpack_stream_reader_get_length;
121 stream_reader->can_seek = gst_wavpack_stream_reader_can_seek;
122 stream_reader->write_bytes = gst_wavpack_stream_reader_write_bytes;
123
124 return stream_reader;
125 }
126