1 /*
2  * Musepack audio files decoder for MPlayer
3  * by Reza Jelveh <reza.jelveh@tuhh.de> and
4  * Reimar Döffinger <Reimar.Doeffinger@stud.uni-karlsruhe.de>
5  *
6  * This code may be be relicensed under the terms of the GNU LGPL when it
7  * becomes part of the FFmpeg project (ffmpeg.org)
8  *
9  * This file is part of MPlayer.
10  *
11  * MPlayer is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * MPlayer is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public License along
22  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
23  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24  */
25 
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <unistd.h>
29 
30 #include "config.h"
31 #include "mp_msg.h"
32 #include "ad_internal.h"
33 #include "libaf/af_format.h"
34 #include "libvo/fastmemcpy.h"
35 
36 static const ad_info_t info =
37 {
38 	"Musepack audio decoder",
39 	"mpcdec",
40 	"Reza Jelveh and Reimar Döffinger",
41 	"",
42 	""
43 };
44 
45 LIBAD_EXTERN(libmusepack)
46 
47 #include <mpcdec/mpcdec.h>
48 
49 // BUFFER_LENGTH is in MPC_SAMPLE_FORMAT units
50 #define MAX_FRAMESIZE (4 * MPC_DECODER_BUFFER_LENGTH)
51 //! this many frames should decode good after seeking
52 #define MIN_SEEK_GOOD 5
53 //! how many frames to discard at most after seeking
54 #define MAX_SEEK_DISCARD 50
55 
56 typedef struct context_s {
57   char *header;
58   int header_len;
59   sh_audio_t *sh;
60   uint32_t pos;
61   mpc_decoder decoder;
62 } context_t;
63 
64 /**
65  * \brief mpc_reader callback function for reading the header
66  */
cb_read(void * data,void * buf,mpc_int32_t size)67 static mpc_int32_t cb_read(void *data, void *buf, mpc_int32_t size) {
68   context_t *d = (context_t *)data;
69   char *p = (char *)buf;
70   int s = size;
71   if (d->pos < d->header_len) {
72     if (s > d->header_len - d->pos)
73       s = d->header_len - d->pos;
74     fast_memcpy(p, &d->header[d->pos], s);
75   } else
76     s = 0;
77   memset(&p[s], 0, size - s);
78   d->pos += size;
79   return size;
80 }
81 
82 /**
83  * \brief dummy mpc_reader callback function for seeking
84  */
cb_seek(void * data,mpc_int32_t offset)85 static mpc_bool_t cb_seek(void *data, mpc_int32_t offset ) {
86   context_t *d = (context_t *)data;
87   d->pos = offset;
88   return 1;
89 }
90 
91 /**
92  * \brief dummy mpc_reader callback function for getting stream position
93  */
cb_tell(void * data)94 static mpc_int32_t cb_tell(void *data) {
95   context_t *d = (context_t *)data;
96   return d->pos;
97 }
98 
99 /**
100  * \brief dummy mpc_reader callback function for getting stream length
101  */
cb_get_size(void * data)102 static mpc_int32_t cb_get_size(void *data) {
103   return 1 << 30;
104 }
105 
106 /**
107  * \brief mpc_reader callback function, we cannot seek.
108  */
cb_canseek(void * data)109 static mpc_bool_t cb_canseek(void *data) {
110   return 0;
111 }
112 
113 
114 mpc_reader header_reader = {
115   .read = cb_read, .seek = cb_seek, .tell = cb_tell,
116   .get_size = cb_get_size, .canseek = cb_canseek
117 };
118 
preinit(sh_audio_t * sh)119 static int preinit(sh_audio_t *sh) {
120   sh->audio_out_minsize = MAX_FRAMESIZE;
121   return 1;
122 }
123 
uninit(sh_audio_t * sh)124 static void uninit(sh_audio_t *sh) {
125   free(sh->context);
126   sh->context = NULL;
127 }
128 
init(sh_audio_t * sh)129 static int init(sh_audio_t *sh) {
130   mpc_streaminfo info;
131   context_t *cd = malloc(sizeof(context_t));
132 
133   if (!sh->wf || (sh->wf->cbSize < 6 * 4)) {
134     mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Missing extradata!\n");
135     return 0;
136   }
137   cd->header = (char *)(sh->wf + 1);
138   cd->header_len = sh->wf->cbSize;
139   cd->sh = sh;
140   cd->pos = 0;
141   sh->context = (char *)cd;
142 
143   /* read file's streaminfo data */
144   mpc_streaminfo_init(&info);
145   header_reader.data = cd;
146   if (mpc_streaminfo_read(&info, &header_reader) != ERROR_CODE_OK) {
147     mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Not a valid musepack file.\n");
148     return 0;
149   }
150 // this value is nonsense, since it relies on the get_size function.
151 // use the value from the demuxer instead.
152 //  sh->i_bps = info.average_bitrate / 8;
153   sh->channels = info.channels;
154   sh->samplerate = info.sample_freq;
155   sh->samplesize = 4;
156   sh->sample_format =
157 #if MPC_SAMPLE_FORMAT == float
158              AF_FORMAT_FLOAT_NE;
159 #elif  MPC_SAMPLE_FORMAT == mpc_int32_t
160              AF_FORMAT_S32_NE;
161 #else
162   #error musepack lib must use either float or mpc_int32_t sample format
163 #endif
164 
165   mpc_decoder_setup(&cd->decoder, NULL);
166   mpc_decoder_set_streaminfo(&cd->decoder, &info);
167   return 1;
168 }
169 
170 // FIXME: minlen is currently ignored
decode_audio(sh_audio_t * sh,unsigned char * buf,int minlen,int maxlen)171 static int decode_audio(sh_audio_t *sh, unsigned char *buf,
172                         int minlen, int maxlen) {
173   int status, len;
174   MPC_SAMPLE_FORMAT *sample_buffer = (MPC_SAMPLE_FORMAT *)buf;
175   mpc_uint32_t *packet = NULL;
176 
177   context_t *cd = (context_t *) sh->context;
178   if (maxlen < MAX_FRAMESIZE) {
179     mp_msg(MSGT_DECAUDIO, MSGL_V, "maxlen too small in decode_audio\n");
180     return -1;
181   }
182   len = ds_get_packet(sh->ds, (unsigned char **)&packet);
183   if (len <= 0) return -1;
184   status = mpc_decoder_decode_frame(&cd->decoder, packet, len, sample_buffer);
185   if (status == -1) // decode error
186     mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Error decoding file.\n");
187   if (status <= 0) // error or EOF
188     return -1;
189 
190   status = MPC_FRAME_LENGTH * sh->channels; // one sample per channel
191 #if MPC_SAMPLE_FORMAT == float || MPC_SAMPLE_FORMAT == mpc_int32_t
192   status *= 4;
193 #else
194   // should not happen
195   status *= 2;
196 #endif
197   return status;
198 }
199 
200 /**
201  * \brief check if the decoded values are in a sane range
202  * \param buf decoded buffer
203  * \param len length of buffer in bytes
204  * \return 1 if all values are in (-1.01, 1.01) range, 0 otherwise
205  */
check_clip(void * buf,int len)206 static int check_clip(void *buf, int len) {
207 #if MPC_SAMPLE_FORMAT == float
208   float *p = buf;
209   if (len < 4) return 1;
210   len = -len / 4;
211   p = &p[-len];
212   do {
213     if (p[len] < -1 || p[len] > 1) return 0;
214   } while (++len);
215 #endif
216   return 1;
217 }
218 
control(sh_audio_t * sh,int cmd,void * arg,...)219 static int control(sh_audio_t *sh, int cmd, void* arg, ...) {
220   if (cmd == ADCTRL_RESYNC_STREAM) {
221     unsigned char *buf = malloc(MAX_FRAMESIZE);
222     int i;
223     int nr_ok = 0;
224     for (i = 0; i < MAX_SEEK_DISCARD; i++) {
225       int len = decode_audio(sh, buf, 0, MAX_FRAMESIZE);
226       if (check_clip(buf, len)) nr_ok++; else nr_ok = 0;
227       if (nr_ok > MIN_SEEK_GOOD) break;
228     }
229     free(buf);
230   }
231   return CONTROL_UNKNOWN;
232 }
233