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/*
* 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/apv.h"
#include "libavcodec/bytestream.h"
#include "avformat.h"
#include "avio_internal.h"
#include "demux.h"
#include "internal.h"
typedef struct APVHeaderInfo {
uint8_t pbu_type;
uint16_t group_id;
uint8_t profile_idc;
uint8_t level_idc;
uint8_t band_idc;
int frame_width;
int frame_height;
uint8_t bit_depth_minus8;
} APVHeaderInfo;
static int apv_extract_header_info(GetByteContext *gbc)
{
APVHeaderInfo header, *info = &header;
int zero, byte;
info->pbu_type = bytestream2_get_byte(gbc);
info->group_id = bytestream2_get_be16(gbc);
zero = bytestream2_get_byte(gbc);
if (zero != 0)
return AVERROR_INVALIDDATA;
if (info->pbu_type == APV_PBU_ACCESS_UNIT_INFORMATION) {
unsigned int num_frames = bytestream2_get_be16(gbc);
if (num_frames < 1)
return AVERROR_INVALIDDATA;
info->pbu_type = bytestream2_get_byte(gbc);
if (info->pbu_type != APV_PBU_PRIMARY_FRAME &&
info->pbu_type != APV_PBU_NON_PRIMARY_FRAME &&
(info->pbu_type < APV_PBU_PREVIEW_FRAME || info->pbu_type > APV_PBU_ALPHA_FRAME))
return AVERROR_INVALIDDATA;
bytestream2_skip(gbc, 2); // group_id
zero = bytestream2_get_byte(gbc);
if (zero != 0)
return AVERROR_INVALIDDATA;
} else if (info->pbu_type != APV_PBU_PRIMARY_FRAME)
return AVERROR_INVALIDDATA;
info->profile_idc = bytestream2_get_byte(gbc);
info->level_idc = bytestream2_get_byte(gbc);
byte = bytestream2_get_byte(gbc);
info->band_idc = byte >> 3;
zero = byte & 7;
if (zero != 0)
return AVERROR_INVALIDDATA;
info->frame_width = bytestream2_get_be24(gbc);
info->frame_height = bytestream2_get_be24(gbc);
if (info->frame_width < 1 || info->frame_width > 65536 ||
info->frame_height < 1 || info->frame_height > 65536)
return AVERROR_INVALIDDATA;
byte = bytestream2_get_byte(gbc);
info->bit_depth_minus8 = byte & 0xf;
if (info->bit_depth_minus8 > 8) {
return AVERROR_INVALIDDATA;
}
if (info->bit_depth_minus8 % 2) {
// Odd bit depths are technically valid but not useful here.
return AVERROR_INVALIDDATA;
}
// Ignore capture_time_distance.
bytestream2_skip(gbc, 1);
zero = bytestream2_get_byte(gbc);
if (zero != 0)
return AVERROR_INVALIDDATA;
return 1;
}
static int apv_probe(const AVProbeData *p)
{
GetByteContext gbc;
uint32_t au_size, signature, pbu_size;
int err;
if (p->buf_size < 28) {
// Too small to fit an APV header.
return 0;
}
bytestream2_init(&gbc, p->buf, p->buf_size);
au_size = bytestream2_get_be32(&gbc);
if (au_size < 24) {
// Too small.
return 0;
}
signature = bytestream2_get_be32(&gbc);
if (signature != APV_SIGNATURE) {
// Signature is mandatory.
return 0;
}
pbu_size = bytestream2_get_be32(&gbc);
if (pbu_size < 16) {
// Too small.
return 0;
}
err = apv_extract_header_info(&gbc);
if (err < 0) {
// Header does not look like APV.
return 0;
}
return AVPROBE_SCORE_MAX;
}
static int apv_read_header(AVFormatContext *s)
{
AVStream *st;
GetByteContext gbc;
uint8_t buffer[12];
uint32_t au_size, signature, pbu_size;
int err, size;
err = ffio_ensure_seekback(s->pb, sizeof(buffer));
if (err < 0)
return err;
size = ffio_read_size(s->pb, buffer, sizeof(buffer));
if (size < 0)
return size;
bytestream2_init(&gbc, buffer, sizeof(buffer));
au_size = bytestream2_get_be32(&gbc);
if (au_size < 24) {
// Too small.
return AVERROR_INVALIDDATA;
}
signature = bytestream2_get_be32(&gbc);
if (signature != APV_SIGNATURE) {
// Signature is mandatory.
return AVERROR_INVALIDDATA;
}
pbu_size = bytestream2_get_be32(&gbc);
if (pbu_size < 16) {
// Too small.
return AVERROR_INVALIDDATA;
}
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_APV;
ffstream(st)->need_parsing = AVSTREAM_PARSE_HEADERS;
st->avg_frame_rate = (AVRational){ 30, 1 };
avpriv_set_pts_info(st, 64, 1, 30);
avio_seek(s->pb, -size, SEEK_CUR);
return 0;
}
static int apv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
uint32_t au_size, signature;
int ret;
au_size = avio_rb32(s->pb);
if (au_size == 0 && avio_feof(s->pb))
return AVERROR_EOF;
if (au_size < 24 || au_size > 1 << 24) {
av_log(s, AV_LOG_ERROR,
"APV AU has invalid size: %"PRIu32"\n", au_size);
return AVERROR_INVALIDDATA;
}
ret = av_get_packet(s->pb, pkt, au_size);
if (ret < 0)
return ret;
pkt->pos -= 4;
pkt->flags = AV_PKT_FLAG_KEY;
signature = AV_RB32(pkt->data);
if (signature != APV_SIGNATURE) {
av_log(s, AV_LOG_ERROR, "APV AU has invalid signature.\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
const FFInputFormat ff_apv_demuxer = {
.p.name = "apv",
.p.long_name = NULL_IF_CONFIG_SMALL("APV raw bitstream"),
.p.extensions = "apv",
.p.flags = AVFMT_GENERIC_INDEX | AVFMT_NOTIMESTAMPS,
.read_probe = apv_probe,
.read_header = apv_read_header,
.read_packet = apv_read_packet,
};
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