1/*
2 * QCP format (.qcp) demuxer
3 * Copyright (c) 2009 Kenan Gillet
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * QCP format (.qcp) demuxer
25 * @author Kenan Gillet
26 * @see RFC 3625: "The QCP File Format and Media Types for Speech Data"
27 *     http://tools.ietf.org/html/rfc3625
28 */
29
30#include "libavutil/channel_layout.h"
31#include "libavutil/intreadwrite.h"
32#include "avformat.h"
33
34typedef struct {
35    uint32_t data_size;                     ///< size of data chunk
36
37#define QCP_MAX_MODE 4
38    int16_t rates_per_mode[QCP_MAX_MODE+1]; ///< contains the packet size corresponding
39                                            ///< to each mode, -1 if no size.
40} QCPContext;
41
42/**
43 * Last 15 out of 16 bytes of QCELP-13K GUID, as stored in the file;
44 * the first byte of the GUID can be either 0x41 or 0x42.
45 */
46static const uint8_t guid_qcelp_13k_part[15] = {
47    0x6d, 0x7f, 0x5e, 0x15, 0xb1, 0xd0, 0x11, 0xba,
48    0x91, 0x00, 0x80, 0x5f, 0xb4, 0xb9, 0x7e
49};
50
51/**
52 * EVRC GUID as stored in the file
53 */
54static const uint8_t guid_evrc[16] = {
55    0x8d, 0xd4, 0x89, 0xe6, 0x76, 0x90, 0xb5, 0x46,
56    0x91, 0xef, 0x73, 0x6a, 0x51, 0x00, 0xce, 0xb4
57};
58
59/**
60 * SMV GUID as stored in the file
61 */
62static const uint8_t guid_smv[16] = {
63    0x75, 0x2b, 0x7c, 0x8d, 0x97, 0xa7, 0x49, 0xed,
64    0x98, 0x5e, 0xd5, 0x3c, 0x8c, 0xc7, 0x5f, 0x84
65};
66
67/**
68 * @param guid contains at least 16 bytes
69 * @return 1 if the guid is a qcelp_13k guid, 0 otherwise
70 */
71static int is_qcelp_13k_guid(const uint8_t *guid) {
72    return (guid[0] == 0x41 || guid[0] == 0x42)
73        && !memcmp(guid+1, guid_qcelp_13k_part, sizeof(guid_qcelp_13k_part));
74}
75
76static int qcp_probe(AVProbeData *pd)
77{
78    if (AV_RL32(pd->buf  ) == AV_RL32("RIFF") &&
79        AV_RL64(pd->buf+8) == AV_RL64("QLCMfmt "))
80        return AVPROBE_SCORE_MAX;
81    return 0;
82}
83
84static int qcp_read_header(AVFormatContext *s)
85{
86    AVIOContext *pb = s->pb;
87    QCPContext    *c  = s->priv_data;
88    AVStream      *st = avformat_new_stream(s, NULL);
89    uint8_t       buf[16];
90    int           i, nb_rates;
91
92    if (!st)
93        return AVERROR(ENOMEM);
94
95    avio_rb32(pb);                    // "RIFF"
96    avio_skip(pb, 4 + 8 + 4 + 1 + 1);    // filesize + "QLCMfmt " + chunk-size + major-version + minor-version
97
98    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
99    st->codec->channels   = 1;
100    st->codec->channel_layout = AV_CH_LAYOUT_MONO;
101    avio_read(pb, buf, 16);
102    if (is_qcelp_13k_guid(buf)) {
103        st->codec->codec_id = AV_CODEC_ID_QCELP;
104    } else if (!memcmp(buf, guid_evrc, 16)) {
105        st->codec->codec_id = AV_CODEC_ID_EVRC;
106    } else if (!memcmp(buf, guid_smv, 16)) {
107        st->codec->codec_id = AV_CODEC_ID_SMV;
108    } else {
109        av_log(s, AV_LOG_ERROR, "Unknown codec GUID.\n");
110        return AVERROR_INVALIDDATA;
111    }
112    avio_skip(pb, 2 + 80); // codec-version + codec-name
113    st->codec->bit_rate = avio_rl16(pb);
114
115    s->packet_size = avio_rl16(pb);
116    avio_skip(pb, 2); // block-size
117    st->codec->sample_rate = avio_rl16(pb);
118    avio_skip(pb, 2); // sample-size
119
120    memset(c->rates_per_mode, -1, sizeof(c->rates_per_mode));
121    nb_rates = avio_rl32(pb);
122    nb_rates = FFMIN(nb_rates, 8);
123    for (i=0; i<nb_rates; i++) {
124        int size = avio_r8(pb);
125        int mode = avio_r8(pb);
126        if (mode > QCP_MAX_MODE) {
127            av_log(s, AV_LOG_WARNING, "Unknown entry %d=>%d in rate-map-table.\n ", mode, size);
128        } else
129            c->rates_per_mode[mode] = size;
130    }
131    avio_skip(pb, 16 - 2*nb_rates + 20); // empty entries of rate-map-table + reserved
132
133    return 0;
134}
135
136static int qcp_read_packet(AVFormatContext *s, AVPacket *pkt)
137{
138    AVIOContext *pb = s->pb;
139    QCPContext    *c  = s->priv_data;
140    unsigned int  chunk_size, tag;
141
142    while(!url_feof(pb)) {
143        if (c->data_size) {
144            int pkt_size, ret, mode = avio_r8(pb);
145
146            if (s->packet_size) {
147                pkt_size = s->packet_size - 1;
148            } else if (mode > QCP_MAX_MODE || (pkt_size = c->rates_per_mode[mode]) < 0) {
149                c->data_size--;
150                continue;
151            }
152
153            if (c->data_size <= pkt_size) {
154                av_log(s, AV_LOG_WARNING, "Data chunk is too small.\n");
155                pkt_size = c->data_size - 1;
156            }
157
158            if ((ret = av_get_packet(pb, pkt, pkt_size)) >= 0) {
159                if (pkt_size != ret)
160                    av_log(s, AV_LOG_ERROR, "Packet size is too small.\n");
161
162                c->data_size -= pkt_size + 1;
163            }
164            return ret;
165        }
166
167        if (avio_tell(pb) & 1 && avio_r8(pb))
168            av_log(s, AV_LOG_WARNING, "Padding should be 0.\n");
169
170        tag        = avio_rl32(pb);
171        chunk_size = avio_rl32(pb);
172        switch (tag) {
173        case MKTAG('v', 'r', 'a', 't'):
174            if (avio_rl32(pb)) // var-rate-flag
175                s->packet_size = 0;
176            avio_skip(pb, 4); // size-in-packets
177            break;
178        case MKTAG('d', 'a', 't', 'a'):
179            c->data_size = chunk_size;
180            break;
181
182        default:
183            avio_skip(pb, chunk_size);
184        }
185    }
186    return AVERROR_EOF;
187}
188
189AVInputFormat ff_qcp_demuxer = {
190    .name           = "qcp",
191    .long_name      = NULL_IF_CONFIG_SMALL("QCP"),
192    .priv_data_size = sizeof(QCPContext),
193    .read_probe     = qcp_probe,
194    .read_header    = qcp_read_header,
195    .read_packet    = qcp_read_packet,
196};
197