Rockbox open source high quality audio player as a Music Player Daemon
mpris
rockbox
mpd
libadwaita
audio
rust
zig
deno
Revert "FS#13299: Simplify VBR frame parsing in the metadata decoder."
This reverts commit 756c0d2ac82515ea8389c69f5f87ca395daca63d.
Change-Id: I5f98972f69e7645239fd9218c9d4eeb9bd2ec7a5
+37
-18
+37
-18
lib/rbcodec/metadata/mp3data.c
+37
-18
lib/rbcodec/metadata/mp3data.c
···
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return header1 ? (header1 == header2) : true;
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}
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+
/* Helper function to read 4-byte in big endian format. */
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static void read_uint32be_mp3data(int fd, unsigned long *data)
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{
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#ifdef ROCKBOX_BIG_ENDIAN
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(void)read(fd, (char*)data, 4);
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#else
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(void)read(fd, (char*)data, 4);
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*data = betoh32(*data);
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#endif
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}
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+
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static unsigned long __find_next_frame(int fd, long *offset, long max_offset,
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unsigned long reference_header,
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int(*getfunc)(int fd, unsigned char *c),
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bool single_header)
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{
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uint32_t header=0;
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uint32_t ref_header=0;
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long ref_header_pos=0;
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unsigned long header=0;
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unsigned char tmp;
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long pos = 0;
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/* We will search until we find two consecutive MPEG frame headers with
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/* We will search until we find two consecutive MPEG frame headers with
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* the same MPEG version, layer and sampling frequency. The first header
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* of this pair is assumed to be the first valid MPEG frame header of the
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* whole stream. */
···
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return 0;
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header |= tmp;
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pos++;
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-
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+
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/* Abort if max_offset is reached. Stop parsing. */
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if (max_offset > 0 && pos > max_offset)
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return 0;
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-
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+
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if (is_mp3frameheader(header)) {
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if (single_header) {
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/* We search for one _single_ valid header that has the same
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* type as the reference_header (if reference_header != 0).
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* type as the reference_header (if reference_header != 0).
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* In this case we are finished. */
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if (headers_have_same_type(reference_header, header))
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break;
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} else {
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/* The current header is valid. Compare it against the last
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one we found. NOTE: ref_header MUST come second! */
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if (headers_have_same_type(header, ref_header)) {
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/* Found a match, return the header and offset of the FIRST */
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header = ref_header;
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lseek(fd, ref_header_pos, SEEK_SET);
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/* The current header is valid. Now gather the frame size,
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* seek to this byte position and check if there is another
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* valid MPEG frame header of the same type. */
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struct mp3info info;
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/* Gather frame size from given header and seek to next
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* frame header. */
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mp3headerinfo(&info, header);
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lseek(fd, info.frame_size-4, SEEK_CUR);
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/* Read possible next frame header and seek back to last frame
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* headers byte position. */
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reference_header = 0;
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read_uint32be_mp3data(fd, &reference_header);
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//
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lseek(fd, -info.frame_size, SEEK_CUR);
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/* If the current header is of the same type as the previous
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* header we are finished. */
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if (headers_have_same_type(header, reference_header))
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break;
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-
}
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/* Otherwise look for another.. */
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ref_header = header;
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ref_header_pos = lseek(fd, 0, SEEK_CUR);
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}
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}
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-
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+
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} while (true);
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*offset = pos - 4;