ref: fa4c2ef5d00c4a136e6b59873151dea46e8d8023
parent: 32a3ae45de25edbee8c232a63b1c0528bc3dbd96
author: lieff <lieff@users.noreply.github.com>
date: Wed Feb 5 14:48:54 EST 2020
mp3dec_ex: support vbr tag for mp3dec_load_buf
--- a/minimp3_ex.h
+++ b/minimp3_ex.h
@@ -127,10 +127,52 @@
*pbuf_size = buf_size;
}
+static int mp3dec_check_vbrtag(const uint8_t *frame, int frame_size, uint32_t *frames, int *delay, int *padding)
+{+ int i;
+ static const char g_xing_tag[4] = { 'X', 'i', 'n', 'g' };+ static const char g_info_tag[4] = { 'I', 'n', 'f', 'o' };+#define FRAMES_FLAG 1
+#define BYTES_FLAG 2
+#define TOC_FLAG 4
+#define VBR_SCALE_FLAG 8
+ /* 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))
+ continue;
+ int flags = tag[7];
+ if (!((flags & FRAMES_FLAG)))
+ break;
+ 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);
+ *padding = (((tag[1] & 0xF) << 8) | tag[2]) - (528 + 1);
+ return 1;
+ }
+ return 0;
+}
+
void mp3dec_load_buf(mp3dec_t *dec, const uint8_t *buf, size_t buf_size, mp3dec_file_info_t *info, MP3D_PROGRESS_CB progress_cb, void *user_data)
{+ uint64_t detected_samples = 0;
size_t orig_buf_size = buf_size;
- mp3d_sample_t pcm[MINIMP3_MAX_SAMPLES_PER_FRAME];
+ int to_skip = 0;
mp3dec_frame_info_t frame_info;
memset(info, 0, sizeof(*info));
memset(&frame_info, 0, sizeof(frame_info));
@@ -138,33 +180,57 @@
mp3dec_skip_id3(&buf, &buf_size);
if (!buf_size)
return;
- /* try to make allocation size assumption by first frame */
+ /* try to make allocation size assumption by first frame or vbr tag */
mp3dec_init(dec);
int samples;
do
{- samples = mp3dec_decode_frame(dec, buf, MINIMP3_MIN(buf_size, (size_t)INT_MAX), pcm, &frame_info);
- buf += frame_info.frame_bytes;
- buf_size -= frame_info.frame_bytes;
- if (samples)
- break;
- } while (frame_info.frame_bytes);
- if (!samples)
- return;
- samples *= frame_info.channels;
- size_t allocated = (buf_size/frame_info.frame_bytes)*samples*sizeof(mp3d_sample_t) + MINIMP3_MAX_SAMPLES_PER_FRAME*sizeof(mp3d_sample_t);
+ uint32_t frames;
+ int delay, padding, free_format_bytes = 0, frame_size = 0;
+ int i = mp3d_find_frame(buf, buf_size, &free_format_bytes, &frame_size);
+ buf += i;
+ buf_size -= i;
+ if (i && !frame_size)
+ continue;
+ if (!frame_size)
+ return;
+ const uint8_t *hdr = buf;
+ frame_info.channels = HDR_IS_MONO(hdr) ? 1 : 2;
+ frame_info.hz = hdr_sample_rate_hz(hdr);
+ frame_info.layer = 4 - HDR_GET_LAYER(hdr);
+ frame_info.bitrate_kbps = hdr_bitrate_kbps(hdr);
+ frame_info.frame_bytes = frame_size;
+ samples = hdr_frame_samples(hdr)*frame_info.channels;
+ if (mp3dec_check_vbrtag(hdr, frame_size, &frames, &delay, &padding))
+ {+ padding *= frame_info.channels;
+ to_skip = delay*frame_info.channels;
+ detected_samples = samples*(uint64_t)frames;
+ if (detected_samples >= (uint64_t)to_skip)
+ detected_samples -= to_skip;
+ if (padding > 0 && detected_samples >= (uint64_t)padding)
+ detected_samples -= padding;
+ if (!detected_samples)
+ return;
+ buf += frame_size;
+ buf_size -= frame_size;
+ }
+ break;
+ } while(1);
+ size_t allocated = MINIMP3_MAX_SAMPLES_PER_FRAME*sizeof(mp3d_sample_t);
+ if (detected_samples)
+ allocated += detected_samples*sizeof(mp3d_sample_t);
+ else
+ allocated += (buf_size/frame_info.frame_bytes)*samples*sizeof(mp3d_sample_t);
info->buffer = (mp3d_sample_t*)malloc(allocated);
if (!info->buffer)
return;
- info->samples = samples;
- memcpy(info->buffer, pcm, info->samples*sizeof(mp3d_sample_t));
/* save info */
info->channels = frame_info.channels;
info->hz = frame_info.hz;
info->layer = frame_info.layer;
- size_t avg_bitrate_kbps = frame_info.bitrate_kbps;
- size_t frames = 1;
- /* decode rest frames */
+ /* decode all frames */
+ size_t avg_bitrate_kbps = 0, frames = 0;
int frame_bytes;
do
{@@ -187,7 +253,15 @@
#else
break;
#endif
- info->samples += samples*frame_info.channels;
+ samples *= frame_info.channels;
+ if (to_skip)
+ {+ size_t skip = MINIMP3_MIN(samples, to_skip);
+ to_skip -= skip;
+ samples -= skip;
+ memmove(info->buffer, info->buffer + skip, samples);
+ }
+ info->samples += samples;
avg_bitrate_kbps += frame_info.bitrate_kbps;
frames++;
if (progress_cb)
@@ -194,10 +268,13 @@
progress_cb(user_data, orig_buf_size, orig_buf_size - buf_size, &frame_info);
}
} while (frame_bytes);
+ if (detected_samples)
+ info->samples = detected_samples;
/* reallocate to normal buffer size */
if (allocated != info->samples*sizeof(mp3d_sample_t))
info->buffer = (mp3d_sample_t*)realloc(info->buffer, info->samples*sizeof(mp3d_sample_t));
- info->avg_bitrate_kbps = avg_bitrate_kbps/frames;
+ if (frames)
+ info->avg_bitrate_kbps = avg_bitrate_kbps/frames;
}
size_t mp3dec_iterate_buf(const uint8_t *buf, size_t buf_size, MP3D_ITERATE_CB callback, void *user_data)
@@ -241,61 +318,29 @@
static int mp3dec_load_index(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)
{- static const char g_xing_tag[4] = { 'X', 'i', 'n', 'g' };- static const char g_info_tag[4] = { 'I', 'n', 'f', 'o' };mp3dec_frame_t *idx_frame;
mp3dec_ex_t *dec = (mp3dec_ex_t *)user_data;
if (!dec->index.frames && !dec->vbr_tag_found)
{ /* detect VBR tag and try to avoid full scan */- int i;
+ uint32_t frames;
+ int delay, padding;
dec->info = *info;
dec->start_offset = dec->offset = offset;
dec->end_offset = offset + buf_size;
dec->free_format_bytes = free_format_bytes; /* should not change */
- /* 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++)
+ if (mp3dec_check_vbrtag(frame, frame_size, &frames, &delay, &padding))
{- const uint8_t *tag = frame + i;
- if (!memcmp(g_xing_tag, tag, 4) || !memcmp(g_info_tag, tag, 4))
- {-#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;
- 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;
- }
+ padding *= info->channels;
+ dec->start_delay = dec->to_skip = delay*info->channels;
+ 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;
}
}
if (dec->index.num_frames + 1 > dec->index.capacity)
--- a/scripts/test_mode.sh
+++ b/scripts/test_mode.sh
@@ -13,7 +13,7 @@
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"
if [ "$MODE" = "2" ]; then
-VECTORS+=" vectors/vbrtag/l3-nonstandard-sin1k0db_lame_tag.bit"
+VECTORS+=" vectors/l3-nonstandard-sin1k0db_lame_vbrtag.bit"
fi
set +e
binary files /dev/null b/vectors/l3-nonstandard-sin1k0db_lame_vbrtag.bit differ
binary files /dev/null b/vectors/l3-nonstandard-sin1k0db_lame_vbrtag.pcm differ
binary files a/vectors/vbrtag/l3-nonstandard-sin1k0db_lame_tag.bit /dev/null differ
binary files a/vectors/vbrtag/l3-nonstandard-sin1k0db_lame_tag.pcm /dev/null differ