1 /***************************************************************************
3 * Open \______ \ ____ ____ | | _\_ |__ _______ ___
4 * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5 * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6 * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
10 * Copyright (C) 2005 Dave Chapman
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
17 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
18 * KIND, either express or implied.
20 ****************************************************************************/
23 #include "libm4a/m4a.h"
24 #include "libalac/decomp.h"
28 /* The maximum buffer size handled. This amount of bytes is buffered for each
30 #define ALAC_BYTE_BUFFER_SIZE 32768
32 static int32_t outputbuffer
[ALAC_MAX_CHANNELS
][ALAC_BLOCKSIZE
] IBSS_ATTR
;
34 /* this is the codec entry point */
35 enum codec_status
codec_main(enum codec_entry_call_reason reason
)
37 if (reason
== CODEC_LOAD
) {
38 /* Generic codec initialisation */
39 ci
->configure(DSP_SET_STEREO_MODE
, STEREO_NONINTERLEAVED
);
40 ci
->configure(DSP_SET_SAMPLE_DEPTH
, ALAC_OUTPUT_DEPTH
-1);
46 /* this is called for each file to process */
47 enum codec_status
codec_run(void)
50 demux_res_t demux_res
;
51 stream_t input_stream
;
53 uint32_t elapsedtime
= 0;
56 unsigned char* buffer
;
60 /* Clean and initialize decoder structures */
61 memset(&demux_res
, 0, sizeof(demux_res
));
63 LOGF("ALAC: Error initialising codec\n");
67 ci
->configure(DSP_SWITCH_FREQUENCY
, ci
->id3
->frequency
);
68 codec_set_replaygain(ci
->id3
);
72 stream_create(&input_stream
,ci
);
74 /* Read from ci->id3->offset before calling qtmovie_read. */
75 samplesdone
= (uint32_t)(((uint64_t)(ci
->id3
->offset
) * ci
->id3
->frequency
) /
76 (ci
->id3
->bitrate
*128));
78 /* if qtmovie_read returns successfully, the stream is up to
79 * the movie data, which can be used directly by the decoder */
80 if (!qtmovie_read(&input_stream
, &demux_res
)) {
81 LOGF("ALAC: Error initialising file\n");
85 /* initialise the sound converter */
86 alac_set_info(&alac
, demux_res
.codecdata
);
88 /* Set i for first frame, seek to desired sample position for resuming. */
90 if (samplesdone
> 0) {
91 if (m4a_seek(&demux_res
, &input_stream
, samplesdone
,
92 &samplesdone
, (int*) &i
)) {
93 elapsedtime
= (samplesdone
* 10) / (ci
->id3
->frequency
/ 100);
94 ci
->set_elapsed(elapsedtime
);
100 ci
->set_elapsed(elapsedtime
);
102 /* The main decoding loop */
103 while (i
< demux_res
.num_sample_byte_sizes
) {
104 enum codec_command_action action
= ci
->get_command(¶m
);
106 if (action
== CODEC_ACTION_HALT
)
109 /* Request the required number of bytes from the input buffer */
110 buffer
=ci
->request_buffer(&n
, ALAC_BYTE_BUFFER_SIZE
);
112 /* Deal with any pending seek requests */
113 if (action
== CODEC_ACTION_SEEK_TIME
) {
114 if (m4a_seek(&demux_res
, &input_stream
,
115 (param
/10) * (ci
->id3
->frequency
/100),
116 &samplesdone
, (int *)&i
)) {
117 elapsedtime
=(samplesdone
*10)/(ci
->id3
->frequency
/100);
119 ci
->set_elapsed(elapsedtime
);
123 /* Request the required number of bytes from the input buffer */
124 buffer
=ci
->request_buffer(&n
, ALAC_BYTE_BUFFER_SIZE
);
126 /* Decode one block - returned samples will be host-endian */
127 samplesdecoded
=alac_decode_frame(&alac
, buffer
, outputbuffer
, ci
->yield
);
130 /* Advance codec buffer by amount of consumed bytes */
131 ci
->advance_buffer(alac
.bytes_consumed
);
133 /* Output the audio */
134 ci
->pcmbuf_insert(outputbuffer
[0], outputbuffer
[1], samplesdecoded
);
136 /* Update the elapsed-time indicator */
137 samplesdone
+=samplesdecoded
;
138 elapsedtime
=(samplesdone
*10)/(ci
->id3
->frequency
/100);
139 ci
->set_elapsed(elapsedtime
);
144 LOGF("ALAC: Decoded %lu samples\n",(unsigned long)samplesdone
);