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-rw-r--r--lib/rbcodec/metadata/mp3data.c55
1 files changed, 37 insertions, 18 deletions
diff --git a/lib/rbcodec/metadata/mp3data.c b/lib/rbcodec/metadata/mp3data.c
index 8c800c798a..83605126d6 100644
--- a/lib/rbcodec/metadata/mp3data.c
+++ b/lib/rbcodec/metadata/mp3data.c
@@ -212,18 +212,27 @@ static bool headers_have_same_type(unsigned long header1,
212 return header1 ? (header1 == header2) : true; 212 return header1 ? (header1 == header2) : true;
213} 213}
214 214
215/* Helper function to read 4-byte in big endian format. */
216static void read_uint32be_mp3data(int fd, unsigned long *data)
217{
218#ifdef ROCKBOX_BIG_ENDIAN
219 (void)read(fd, (char*)data, 4);
220#else
221 (void)read(fd, (char*)data, 4);
222 *data = betoh32(*data);
223#endif
224}
225
215static unsigned long __find_next_frame(int fd, long *offset, long max_offset, 226static unsigned long __find_next_frame(int fd, long *offset, long max_offset,
216 unsigned long reference_header, 227 unsigned long reference_header,
217 int(*getfunc)(int fd, unsigned char *c), 228 int(*getfunc)(int fd, unsigned char *c),
218 bool single_header) 229 bool single_header)
219{ 230{
220 uint32_t header=0; 231 unsigned long header=0;
221 uint32_t ref_header=0;
222 long ref_header_pos=0;
223 unsigned char tmp; 232 unsigned char tmp;
224 long pos = 0; 233 long pos = 0;
225 234
226 /* We will search until we find two consecutive MPEG frame headers with 235 /* We will search until we find two consecutive MPEG frame headers with
227 * the same MPEG version, layer and sampling frequency. The first header 236 * the same MPEG version, layer and sampling frequency. The first header
228 * of this pair is assumed to be the first valid MPEG frame header of the 237 * of this pair is assumed to be the first valid MPEG frame header of the
229 * whole stream. */ 238 * whole stream. */
@@ -234,33 +243,43 @@ static unsigned long __find_next_frame(int fd, long *offset, long max_offset,
234 return 0; 243 return 0;
235 header |= tmp; 244 header |= tmp;
236 pos++; 245 pos++;
237 246
238 /* Abort if max_offset is reached. Stop parsing. */ 247 /* Abort if max_offset is reached. Stop parsing. */
239 if (max_offset > 0 && pos > max_offset) 248 if (max_offset > 0 && pos > max_offset)
240 return 0; 249 return 0;
241 250
242 if (is_mp3frameheader(header)) { 251 if (is_mp3frameheader(header)) {
243 if (single_header) { 252 if (single_header) {
244 /* We search for one _single_ valid header that has the same 253 /* We search for one _single_ valid header that has the same
245 * type as the reference_header (if reference_header != 0). 254 * type as the reference_header (if reference_header != 0).
246 * In this case we are finished. */ 255 * In this case we are finished. */
247 if (headers_have_same_type(reference_header, header)) 256 if (headers_have_same_type(reference_header, header))
248 break; 257 break;
249 } else { 258 } else {
250 /* The current header is valid. Compare it against the last 259 /* The current header is valid. Now gather the frame size,
251 one we found. NOTE: ref_header MUST come second! */ 260 * seek to this byte position and check if there is another
252 if (headers_have_same_type(header, ref_header)) { 261 * valid MPEG frame header of the same type. */
253 /* Found a match, return the header and offset of the FIRST */ 262 struct mp3info info;
254 header = ref_header; 263
255 lseek(fd, ref_header_pos, SEEK_SET); 264 /* Gather frame size from given header and seek to next
265 * frame header. */
266 mp3headerinfo(&info, header);
267 lseek(fd, info.frame_size-4, SEEK_CUR);
268
269 /* Read possible next frame header and seek back to last frame
270 * headers byte position. */
271 reference_header = 0;
272 read_uint32be_mp3data(fd, &reference_header);
273 //
274 lseek(fd, -info.frame_size, SEEK_CUR);
275
276 /* If the current header is of the same type as the previous
277 * header we are finished. */
278 if (headers_have_same_type(header, reference_header))
256 break; 279 break;
257 }
258 /* Otherwise look for another.. */
259 ref_header = header;
260 ref_header_pos = lseek(fd, 0, SEEK_CUR);
261 } 280 }
262 } 281 }
263 282
264 } while (true); 283 } while (true);
265 284
266 *offset = pos - 4; 285 *offset = pos - 4;