ref: 32a3ae45de25edbee8c232a63b1c0528bc3dbd96
parent: 5904e0f2d75f9bc900224692f12793a9a00f78b5
author: lieff <lieff@users.noreply.github.com>
date: Tue Feb 4 21:09:46 EST 2020
mp3dec_ex: support delay and padding from vbr tag + test
--- a/minimp3_ex.h
+++ b/minimp3_ex.h
@@ -50,7 +50,7 @@
mp3dec_t mp3d;
mp3dec_map_info_t file;
mp3dec_index_t index;
- uint64_t offset, samples, start_offset, end_offset;
+ uint64_t offset, samples, detected_samples, start_offset, end_offset;
mp3dec_frame_info_t info;
mp3d_sample_t buffer[MINIMP3_MAX_SAMPLES_PER_FRAME];
#ifndef MINIMP3_NO_STDIO
@@ -58,7 +58,7 @@
#endif
int free_format_bytes;
int seek_method, vbr_tag_found;
- int buffer_samples, buffer_consumed, to_skip;
+ int buffer_samples, buffer_consumed, to_skip, start_delay;
} mp3dec_ex_t;
typedef int (*MP3D_ITERATE_CB)(void *user_data, const uint8_t *frame, int frame_size, int free_format_bytes, size_t buf_size, size_t offset, mp3dec_frame_info_t *info);
@@ -249,18 +249,50 @@
{ /* detect VBR tag and try to avoid full scan */int i;
dec->info = *info;
- dec->start_offset = offset;
+ dec->start_offset = dec->offset = offset;
dec->end_offset = offset + buf_size;
dec->free_format_bytes = free_format_bytes; /* should not change */
- for (i = 5; i < frame_size - 12; i++)
+ /* TODO: skip side-info?
+ / Side info offsets afrer header:
+ / Mono Stereo
+ / MPEG1 17 32
+ / MPEG2 & 2.5 9 17*/
+ for (i = 5; i < frame_size - 36; i++)
{const uint8_t *tag = frame + i;
if (!memcmp(g_xing_tag, tag, 4) || !memcmp(g_info_tag, tag, 4))
{- if (!((tag[7] & 1))/* frames field present */)
+#define FRAMES_FLAG 1
+#define BYTES_FLAG 2
+#define TOC_FLAG 4
+#define VBR_SCALE_FLAG 8
+ int flags = tag[7], delay, padding;
+ uint32_t frames;
+ if (!((flags & FRAMES_FLAG)))
break;
- uint64_t frames = (uint32_t)(tag[8] << 24) | (tag[9] << 16) | (tag[10] << 8) | tag[11];
- dec->samples += hdr_frame_samples(frame)*info->channels*frames;
+ tag += 8;
+ frames = (uint32_t)(tag[0] << 24) | (tag[1] << 16) | (tag[2] << 8) | tag[3];
+ tag += 4;
+ if (flags & BYTES_FLAG)
+ tag += 4;
+ if (flags & TOC_FLAG)
+ tag += 100;
+ if (flags & VBR_SCALE_FLAG)
+ tag += 4;
+ tag += 21;
+ if (tag - frame + 2 >= frame_size)
+ break;
+ delay = (((tag[0] << 4) | (tag[1] >> 4)) + (528 + 1))*info->channels;
+ padding = ((((tag[1] & 0xF) << 8) | tag[2]) - (528 + 1))*info->channels;
+
+ dec->start_delay = dec->to_skip = delay;
+ dec->samples = hdr_frame_samples(frame)*info->channels*(uint64_t)frames;
+ if (dec->samples >= (uint64_t)dec->start_delay)
+ dec->samples -= dec->start_delay;
+ if (padding > 0 && dec->samples >= (uint64_t)padding)
+ dec->samples -= padding;
+ dec->detected_samples = dec->samples;
+ dec->start_offset = dec->offset = offset + frame_size;
dec->vbr_tag_found = 1;
return 1;
}
@@ -296,10 +328,13 @@
dec->file.size = buf_size;
dec->seek_method = seek_method;
mp3dec_init(&dec->mp3d);
- if (mp3dec_iterate_buf(dec->file.buffer, dec->file.size, mp3dec_load_index, dec) > 0 && !dec->index.frames && !dec->vbr_tag_found)
- return MP3D_E_MEMORY;
- mp3dec_init(&dec->mp3d);
- dec->buffer_samples = 0;
+ if (MP3D_SEEK_TO_SAMPLE == dec->seek_method)
+ {+ if (mp3dec_iterate_buf(dec->file.buffer, dec->file.size, mp3dec_load_index, dec) > 0 && !dec->index.frames && !dec->vbr_tag_found)
+ return MP3D_E_MEMORY;
+ mp3dec_init(&dec->mp3d);
+ dec->buffer_samples = 0;
+ }
return 0;
}
@@ -335,6 +370,7 @@
dec->offset = position;
return 0;
}
+ position += dec->start_delay;
if (0 == position)
{ /* optimize seek to zero, no index needed */seek_zero:
@@ -346,8 +382,11 @@
{ /* no index created yet (vbr tag used to calculate track length) */dec->samples = 0;
dec->buffer_samples = 0;
- if (mp3dec_iterate_buf(dec->file.buffer, dec->file.size, mp3dec_load_index, dec) > 0 && !dec->index.frames)
+ if (mp3dec_iterate_buf(dec->file.buffer + dec->start_offset, dec->file.size - dec->start_offset, mp3dec_load_index, dec) > 0 && !dec->index.frames)
return MP3D_E_MEMORY;
+ for (i = 0; i < dec->index.num_frames; i++)
+ dec->index.frames[i].offset += dec->start_offset;
+ dec->samples = dec->detected_samples;
}
if (!dec->index.frames)
goto seek_zero; /* no frames in file - seek to zero */
--- a/scripts/test_mode.sh
+++ b/scripts/test_mode.sh
@@ -7,13 +7,17 @@
APP=./minimp3
MODE=$1
POSITION=$2
-
-set +e
-for i in vectors/l3-compl.bit vectors/l3-he_32khz.bit vectors/l3-he_44khz.bit vectors/l3-he_48khz.bit \
+VECTORS="vectors/l3-compl.bit vectors/l3-he_32khz.bit vectors/l3-he_44khz.bit vectors/l3-he_48khz.bit \
vectors/l3-hecommon.bit vectors/l3-he_mode.bit vectors/l3-si.bit vectors/l3-si_block.bit vectors/l3-si_huff.bit \
vectors/l3-sin1k0db.bit vectors/l3-test45.bit vectors/l3-test46.bit vectors/M2L3_bitrate_16_all.bit \
vectors/M2L3_bitrate_22_all.bit vectors/M2L3_bitrate_24_all.bit vectors/M2L3_compl24.bit vectors/M2L3_noise.bit \
-vectors/l3-nonstandard-id3v1.bit vectors/l3-nonstandard-id3v2.bit vectors/l1-fl1.bit vectors/l2-fl10.bit; do
+vectors/l3-nonstandard-id3v1.bit vectors/l3-nonstandard-id3v2.bit vectors/l1-fl1.bit vectors/l2-fl10.bit"
+if [ "$MODE" = "2" ]; then
+VECTORS+=" vectors/vbrtag/l3-nonstandard-sin1k0db_lame_tag.bit"
+fi
+
+set +e
+for i in $VECTORS; do
$APP -m $MODE -s $POSITION $i ${i%.*}.pcmretval=$?
echo -m $MODE -s $POSITION $i exited with code=$retval
binary files /dev/null b/vectors/vbrtag/l3-nonstandard-sin1k0db_lame_tag.bit differ
binary files /dev/null b/vectors/vbrtag/l3-nonstandard-sin1k0db_lame_tag.pcm differ