FFmpeg/libavformat/qcp.c

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/*
* QCP format (.qcp) demuxer
* Copyright (c) 2009 Kenan Gillet
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* QCP format (.qcp) demuxer
* @author Kenan Gillet
* @see RFC 3625: "The QCP File Format and Media Types for Speech Data"
* http://tools.ietf.org/html/rfc3625
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
typedef struct {
uint32_t data_size; ///< size of data chunk
#define QCP_MAX_MODE 4
int16_t rates_per_mode[QCP_MAX_MODE+1]; ///< contains the packet size corresponding
///< to each mode, -1 if no size.
} QCPContext;
/**
* Last 15 out of 16 bytes of QCELP-13K GUID, as stored in the file;
* the first byte of the GUID can be either 0x41 or 0x42.
*/
static const uint8_t guid_qcelp_13k_part[15] = {
0x6d, 0x7f, 0x5e, 0x15, 0xb1, 0xd0, 0x11, 0xba,
0x91, 0x00, 0x80, 0x5f, 0xb4, 0xb9, 0x7e
};
/**
* EVRC GUID as stored in the file
*/
static const uint8_t guid_evrc[16] = {
0x8d, 0xd4, 0x89, 0xe6, 0x76, 0x90, 0xb5, 0x46,
0x91, 0xef, 0x73, 0x6a, 0x51, 0x00, 0xce, 0xb4
};
/**
* SMV GUID as stored in the file
*/
static const uint8_t guid_smv[16] = {
0x75, 0x2b, 0x7c, 0x8d, 0x97, 0xa7, 0x49, 0xed,
0x98, 0x5e, 0xd5, 0x3c, 0x8c, 0xc7, 0x5f, 0x84
};
/**
* @param guid contains at least 16 bytes
* @return 1 if the guid is a qcelp_13k guid, 0 otherwise
*/
static int is_qcelp_13k_guid(const uint8_t *guid) {
return (guid[0] == 0x41 || guid[0] == 0x42)
&& !memcmp(guid+1, guid_qcelp_13k_part, sizeof(guid_qcelp_13k_part));
}
static int qcp_probe(AVProbeData *pd)
{
if (AV_RL32(pd->buf ) == AV_RL32("RIFF") &&
AV_RL64(pd->buf+8) == AV_RL64("QLCMfmt "))
return AVPROBE_SCORE_MAX;
return 0;
}
static int qcp_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
QCPContext *c = s->priv_data;
AVStream *st = avformat_new_stream(s, NULL);
uint8_t buf[16];
int i, nb_rates;
if (!st)
return AVERROR(ENOMEM);
avio_rb32(pb); // "RIFF"
avio_skip(pb, 4 + 8 + 4 + 1 + 1); // filesize + "QLCMfmt " + chunk-size + major-version + minor-version
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->channels = 1;
avio_read(pb, buf, 16);
if (is_qcelp_13k_guid(buf)) {
st->codec->codec_id = AV_CODEC_ID_QCELP;
} else if (!memcmp(buf, guid_evrc, 16)) {
av_log(s, AV_LOG_ERROR, "EVRC codec is not supported.\n");
return AVERROR_PATCHWELCOME;
} else if (!memcmp(buf, guid_smv, 16)) {
av_log(s, AV_LOG_ERROR, "SMV codec is not supported.\n");
return AVERROR_PATCHWELCOME;
} else {
av_log(s, AV_LOG_ERROR, "Unknown codec GUID.\n");
return AVERROR_INVALIDDATA;
}
avio_skip(pb, 2 + 80); // codec-version + codec-name
st->codec->bit_rate = avio_rl16(pb);
s->packet_size = avio_rl16(pb);
avio_skip(pb, 2); // block-size
st->codec->sample_rate = avio_rl16(pb);
avio_skip(pb, 2); // sample-size
memset(c->rates_per_mode, -1, sizeof(c->rates_per_mode));
nb_rates = avio_rl32(pb);
nb_rates = FFMIN(nb_rates, 8);
for (i=0; i<nb_rates; i++) {
int size = avio_r8(pb);
int mode = avio_r8(pb);
if (mode > QCP_MAX_MODE) {
av_log(s, AV_LOG_WARNING, "Unknown entry %d=>%d in rate-map-table.\n ", mode, size);
} else
c->rates_per_mode[mode] = size;
}
avio_skip(pb, 16 - 2*nb_rates + 20); // empty entries of rate-map-table + reserved
return 0;
}
static int qcp_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
QCPContext *c = s->priv_data;
unsigned int chunk_size, tag;
while(!pb->eof_reached) {
if (c->data_size) {
int pkt_size, ret, mode = avio_r8(pb);
if (s->packet_size) {
pkt_size = s->packet_size - 1;
} else if (mode > QCP_MAX_MODE || (pkt_size = c->rates_per_mode[mode]) < 0) {
c->data_size--;
continue;
}
if (c->data_size <= pkt_size) {
av_log(s, AV_LOG_WARNING, "Data chunk is too small.\n");
pkt_size = c->data_size - 1;
}
if ((ret = av_get_packet(pb, pkt, pkt_size)) >= 0) {
if (pkt_size != ret)
av_log(s, AV_LOG_ERROR, "Packet size is too small.\n");
c->data_size -= pkt_size + 1;
}
return ret;
}
if (avio_tell(pb) & 1 && avio_r8(pb))
av_log(s, AV_LOG_WARNING, "Padding should be 0.\n");
tag = avio_rl32(pb);
chunk_size = avio_rl32(pb);
switch (tag) {
case MKTAG('v', 'r', 'a', 't'):
if (avio_rl32(pb)) // var-rate-flag
s->packet_size = 0;
avio_skip(pb, 4); // size-in-packets
break;
case MKTAG('d', 'a', 't', 'a'):
c->data_size = chunk_size;
break;
default:
avio_skip(pb, chunk_size);
}
}
return AVERROR_EOF;
}
AVInputFormat ff_qcp_demuxer = {
.name = "qcp",
.long_name = NULL_IF_CONFIG_SMALL("QCP"),
.priv_data_size = sizeof(QCPContext),
.read_probe = qcp_probe,
.read_header = qcp_read_header,
.read_packet = qcp_read_packet,
};