making act segmenter

1 files changed, 317 insertions, 0 deletions

diff --git a/ffmpeg/libavformat/mpc8.c b/ffmpeg/libavformat/mpc8.c
new file mode 100644
index 0000000..73f8057
--- /dev/null
+++ b/ffmpeg/libavformat/mpc8.c
@@ -0,0 +1,317 @@
+/*
+ * Musepack SV8 demuxer
+ * Copyright (c) 2007 Konstantin Shishkov
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavcodec/get_bits.h"
+#include "libavcodec/unary.h"
+#include "apetag.h"
+#include "avformat.h"
+#include "internal.h"
+#include "avio_internal.h"
+
+/// Two-byte MPC tag
+#define MKMPCTAG(a, b) (a | (b << 8))
+
+#define TAG_MPCK MKTAG('M','P','C','K')
+
+/// Reserved MPC tags
+enum MPCPacketTags{
+    TAG_STREAMHDR   = MKMPCTAG('S','H'),
+    TAG_STREAMEND   = MKMPCTAG('S','E'),
+
+    TAG_AUDIOPACKET = MKMPCTAG('A','P'),
+
+    TAG_SEEKTBLOFF  = MKMPCTAG('S','O'),
+    TAG_SEEKTABLE   = MKMPCTAG('S','T'),
+
+    TAG_REPLAYGAIN  = MKMPCTAG('R','G'),
+    TAG_ENCINFO     = MKMPCTAG('E','I'),
+};
+
+static const int mpc8_rate[8] = { 44100, 48000, 37800, 32000, -1, -1, -1, -1 };
+
+typedef struct {
+    int ver;
+    int64_t header_pos;
+    int64_t samples;
+
+    int64_t apetag_start;
+} MPCContext;
+
+static inline int64_t bs_get_v(const uint8_t **bs)
+{
+    int64_t v = 0;
+    int br = 0;
+    int c;
+
+    do {
+        c = **bs; (*bs)++;
+        v <<= 7;
+        v |= c & 0x7F;
+        br++;
+        if (br > 10)
+            return -1;
+    } while (c & 0x80);
+
+    return v - br;
+}
+
+static int mpc8_probe(AVProbeData *p)
+{
+    const uint8_t *bs = p->buf + 4;
+    const uint8_t *bs_end = bs + p->buf_size;
+    int64_t size;
+
+    if (p->buf_size < 16)
+        return 0;
+    if (AV_RL32(p->buf) != TAG_MPCK)
+        return 0;
+    while (bs < bs_end + 3) {
+        int header_found = (bs[0] == 'S' && bs[1] == 'H');
+        if (bs[0] < 'A' || bs[0] > 'Z' || bs[1] < 'A' || bs[1] > 'Z')
+            return 0;
+        bs += 2;
+        size = bs_get_v(&bs);
+        if (size < 2)
+            return 0;
+        if (bs + size - 2 >= bs_end)
+            return AVPROBE_SCORE_MAX / 4 - 1; //seems to be valid MPC but no header yet
+        if (header_found) {
+            if (size < 11 || size > 28)
+                return 0;
+            if (!AV_RL32(bs)) //zero CRC is invalid
+                return 0;
+            return AVPROBE_SCORE_MAX;
+        } else {
+            bs += size - 2;
+        }
+    }
+    return 0;
+}
+
+static inline int64_t gb_get_v(GetBitContext *gb)
+{
+    int64_t v = 0;
+    int bits = 0;
+    while(get_bits1(gb) && bits < 64-7){
+        v <<= 7;
+        v |= get_bits(gb, 7);
+        bits += 7;
+    }
+    v <<= 7;
+    v |= get_bits(gb, 7);
+
+    return v;
+}
+
+static void mpc8_get_chunk_header(AVIOContext *pb, int *tag, int64_t *size)
+{
+    int64_t pos;
+    pos = avio_tell(pb);
+    *tag = avio_rl16(pb);
+    *size = ffio_read_varlen(pb);
+    *size -= avio_tell(pb) - pos;
+}
+
+static void mpc8_parse_seektable(AVFormatContext *s, int64_t off)
+{
+    MPCContext *c = s->priv_data;
+    int tag;
+    int64_t size, pos, ppos[2];
+    uint8_t *buf;
+    int i, t, seekd;
+    GetBitContext gb;
+
+    if (s->nb_streams<=0) {
+        av_log(s, AV_LOG_ERROR, "cannot parse stream table before stream header\n");
+        return;
+    }
+
+    avio_seek(s->pb, off, SEEK_SET);
+    mpc8_get_chunk_header(s->pb, &tag, &size);
+    if(tag != TAG_SEEKTABLE){
+        av_log(s, AV_LOG_ERROR, "No seek table at given position\n");
+        return;
+    }
+    if (size > INT_MAX/10 || size<=0) {
+        av_log(s, AV_LOG_ERROR, "Seek table size is invalid\n");
+        return;
+    }
+    if(!(buf = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE)))
+        return;
+    avio_read(s->pb, buf, size);
+    init_get_bits(&gb, buf, size * 8);
+    size = gb_get_v(&gb);
+    if(size > UINT_MAX/4 || size > c->samples/1152){
+        av_log(s, AV_LOG_ERROR, "Seek table is too big\n");
+        return;
+    }
+    seekd = get_bits(&gb, 4);
+    for(i = 0; i < 2; i++){
+        pos = gb_get_v(&gb) + c->header_pos;
+        ppos[1 - i] = pos;
+        av_add_index_entry(s->streams[0], pos, i, 0, 0, AVINDEX_KEYFRAME);
+    }
+    for(; i < size; i++){
+        t = get_unary(&gb, 1, 33) << 12;
+        t += get_bits(&gb, 12);
+        if(t & 1)
+            t = -(t & ~1);
+        pos = (t >> 1) + ppos[0]*2 - ppos[1];
+        av_add_index_entry(s->streams[0], pos, i << seekd, 0, 0, AVINDEX_KEYFRAME);
+        ppos[1] = ppos[0];
+        ppos[0] = pos;
+    }
+    av_free(buf);
+}
+
+static void mpc8_handle_chunk(AVFormatContext *s, int tag, int64_t chunk_pos, int64_t size)
+{
+    AVIOContext *pb = s->pb;
+    int64_t pos, off;
+
+    switch(tag){
+    case TAG_SEEKTBLOFF:
+        pos = avio_tell(pb) + size;
+        off = ffio_read_varlen(pb);
+        mpc8_parse_seektable(s, chunk_pos + off);
+        avio_seek(pb, pos, SEEK_SET);
+        break;
+    default:
+        avio_skip(pb, size);
+    }
+}
+
+static int mpc8_read_header(AVFormatContext *s)
+{
+    MPCContext *c = s->priv_data;
+    AVIOContext *pb = s->pb;
+    AVStream *st;
+    int tag = 0;
+    int64_t size, pos;
+
+    c->header_pos = avio_tell(pb);
+    if(avio_rl32(pb) != TAG_MPCK){
+        av_log(s, AV_LOG_ERROR, "Not a Musepack8 file\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    while(!url_feof(pb)){
+        pos = avio_tell(pb);
+        mpc8_get_chunk_header(pb, &tag, &size);
+        if(tag == TAG_STREAMHDR)
+            break;
+        mpc8_handle_chunk(s, tag, pos, size);
+    }
+    if(tag != TAG_STREAMHDR){
+        av_log(s, AV_LOG_ERROR, "Stream header not found\n");
+        return AVERROR_INVALIDDATA;
+    }
+    pos = avio_tell(pb);
+    avio_skip(pb, 4); //CRC
+    c->ver = avio_r8(pb);
+    if(c->ver != 8){
+        av_log(s, AV_LOG_ERROR, "Unknown stream version %d\n", c->ver);
+        return AVERROR_PATCHWELCOME;
+    }
+    c->samples = ffio_read_varlen(pb);
+    ffio_read_varlen(pb); //silence samples at the beginning
+
+    st = avformat_new_stream(s, NULL);
+    if (!st)
+        return AVERROR(ENOMEM);
+    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+    st->codec->codec_id = AV_CODEC_ID_MUSEPACK8;
+    st->codec->bits_per_coded_sample = 16;
+
+    st->codec->extradata_size = 2;
+    st->codec->extradata = av_mallocz(st->codec->extradata_size + FF_INPUT_BUFFER_PADDING_SIZE);
+    avio_read(pb, st->codec->extradata, st->codec->extradata_size);
+
+    st->codec->channels = (st->codec->extradata[1] >> 4) + 1;
+    st->codec->sample_rate = mpc8_rate[st->codec->extradata[0] >> 5];
+    avpriv_set_pts_info(st, 32, 1152  << (st->codec->extradata[1]&3)*2, st->codec->sample_rate);
+    st->start_time = 0;
+    st->duration = c->samples / (1152 << (st->codec->extradata[1]&3)*2);
+    size -= avio_tell(pb) - pos;
+    if (size > 0)
+        avio_skip(pb, size);
+
+    if (pb->seekable) {
+        int64_t pos = avio_tell(s->pb);
+        c->apetag_start = ff_ape_parse_tag(s);
+        avio_seek(s->pb, pos, SEEK_SET);
+    }
+
+    return 0;
+}
+
+static int mpc8_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    MPCContext *c = s->priv_data;
+    int tag;
+    int64_t pos, size;
+
+    while(!url_feof(s->pb)){
+        pos = avio_tell(s->pb);
+
+        /* don't return bogus packets with the ape tag data */
+        if (c->apetag_start && pos >= c->apetag_start)
+            return AVERROR_EOF;
+
+        mpc8_get_chunk_header(s->pb, &tag, &size);
+        if (size < 0)
+            return -1;
+        if(tag == TAG_AUDIOPACKET){
+            if(av_get_packet(s->pb, pkt, size) < 0)
+                return AVERROR(ENOMEM);
+            pkt->stream_index = 0;
+            pkt->duration     = 1;
+            return 0;
+        }
+        if(tag == TAG_STREAMEND)
+            return AVERROR(EIO);
+        mpc8_handle_chunk(s, tag, pos, size);
+    }
+    return AVERROR_EOF;
+}
+
+static int mpc8_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
+{
+    AVStream *st = s->streams[stream_index];
+    int index = av_index_search_timestamp(st, timestamp, flags);
+
+    if(index < 0) return -1;
+    if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
+        return -1;
+    ff_update_cur_dts(s, st, st->index_entries[index].timestamp);
+    return 0;
+}
+
+
+AVInputFormat ff_mpc8_demuxer = {
+    .name           = "mpc8",
+    .long_name      = NULL_IF_CONFIG_SMALL("Musepack SV8"),
+    .priv_data_size = sizeof(MPCContext),
+    .read_probe     = mpc8_probe,
+    .read_header    = mpc8_read_header,
+    .read_packet    = mpc8_read_packet,
+    .read_seek      = mpc8_read_seek,
+};