yading@11: /*
yading@11:  * TechnoTrend PVA (.pva) demuxer
yading@11:  * Copyright (c) 2007, 2008 Ivo van Poorten
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "avformat.h"
yading@11: #include "internal.h"
yading@11: #include "mpeg.h"
yading@11: 
yading@11: #define PVA_MAX_PAYLOAD_LENGTH  0x17f8
yading@11: #define PVA_VIDEO_PAYLOAD       0x01
yading@11: #define PVA_AUDIO_PAYLOAD       0x02
yading@11: #define PVA_MAGIC               (('A' << 8) + 'V')
yading@11: 
yading@11: typedef struct {
yading@11:     int continue_pes;
yading@11: } PVAContext;
yading@11: 
yading@11: static int pva_check(const uint8_t *p) {
yading@11:     int length = AV_RB16(p + 6);
yading@11:     if (AV_RB16(p) != PVA_MAGIC || !p[2] || p[2] > 2 || p[4] != 0x55 ||
yading@11:         (p[5] & 0xe0) || length > PVA_MAX_PAYLOAD_LENGTH)
yading@11:         return -1;
yading@11:     return length + 8;
yading@11: }
yading@11: 
yading@11: static int pva_probe(AVProbeData * pd) {
yading@11:     const unsigned char *buf = pd->buf;
yading@11:     int len = pva_check(buf);
yading@11: 
yading@11:     if (len < 0)
yading@11:         return 0;
yading@11: 
yading@11:     if (pd->buf_size >= len + 8 &&
yading@11:         pva_check(buf + len) >= 0)
yading@11:         return AVPROBE_SCORE_MAX / 2;
yading@11: 
yading@11:     return AVPROBE_SCORE_MAX / 4;
yading@11: }
yading@11: 
yading@11: static int pva_read_header(AVFormatContext *s) {
yading@11:     AVStream *st;
yading@11: 
yading@11:     if (!(st = avformat_new_stream(s, NULL)))
yading@11:         return AVERROR(ENOMEM);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
yading@11:     st->codec->codec_id   = AV_CODEC_ID_MPEG2VIDEO;
yading@11:     st->need_parsing      = AVSTREAM_PARSE_FULL;
yading@11:     avpriv_set_pts_info(st, 32, 1, 90000);
yading@11:     av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME);
yading@11: 
yading@11:     if (!(st = avformat_new_stream(s, NULL)))
yading@11:         return AVERROR(ENOMEM);
yading@11:     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
yading@11:     st->codec->codec_id   = AV_CODEC_ID_MP2;
yading@11:     st->need_parsing      = AVSTREAM_PARSE_FULL;
yading@11:     avpriv_set_pts_info(st, 33, 1, 90000);
yading@11:     av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME);
yading@11: 
yading@11:     /* the parameters will be extracted from the compressed bitstream */
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: #define pva_log if (read_packet) av_log
yading@11: 
yading@11: static int read_part_of_packet(AVFormatContext *s, int64_t *pts,
yading@11:                                int *len, int *strid, int read_packet) {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     PVAContext *pvactx = s->priv_data;
yading@11:     int syncword, streamid, reserved, flags, length, pts_flag;
yading@11:     int64_t pva_pts = AV_NOPTS_VALUE, startpos;
yading@11: 
yading@11: recover:
yading@11:     startpos = avio_tell(pb);
yading@11: 
yading@11:     syncword = avio_rb16(pb);
yading@11:     streamid = avio_r8(pb);
yading@11:     avio_r8(pb);               /* counter not used */
yading@11:     reserved = avio_r8(pb);
yading@11:     flags    = avio_r8(pb);
yading@11:     length   = avio_rb16(pb);
yading@11: 
yading@11:     pts_flag = flags & 0x10;
yading@11: 
yading@11:     if (syncword != PVA_MAGIC) {
yading@11:         pva_log(s, AV_LOG_ERROR, "invalid syncword\n");
yading@11:         return AVERROR(EIO);
yading@11:     }
yading@11:     if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) {
yading@11:         pva_log(s, AV_LOG_ERROR, "invalid streamid\n");
yading@11:         return AVERROR(EIO);
yading@11:     }
yading@11:     if (reserved != 0x55) {
yading@11:         pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n");
yading@11:     }
yading@11:     if (length > PVA_MAX_PAYLOAD_LENGTH) {
yading@11:         pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length);
yading@11:         return AVERROR(EIO);
yading@11:     }
yading@11: 
yading@11:     if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) {
yading@11:         pva_pts = avio_rb32(pb);
yading@11:         length -= 4;
yading@11:     } else if (streamid == PVA_AUDIO_PAYLOAD) {
yading@11:         /* PVA Audio Packets either start with a signaled PES packet or
yading@11:          * are a continuation of the previous PES packet. New PES packets
yading@11:          * always start at the beginning of a PVA Packet, never somewhere in
yading@11:          * the middle. */
yading@11:         if (!pvactx->continue_pes) {
yading@11:             int pes_signal, pes_header_data_length, pes_packet_length,
yading@11:                 pes_flags;
yading@11:             unsigned char pes_header_data[256];
yading@11: 
yading@11:             pes_signal             = avio_rb24(pb);
yading@11:             avio_r8(pb);
yading@11:             pes_packet_length      = avio_rb16(pb);
yading@11:             pes_flags              = avio_rb16(pb);
yading@11:             pes_header_data_length = avio_r8(pb);
yading@11: 
yading@11:             if (pes_signal != 1) {
yading@11:                 pva_log(s, AV_LOG_WARNING, "expected signaled PES packet, "
yading@11:                                           "trying to recover\n");
yading@11:                 avio_skip(pb, length - 9);
yading@11:                 if (!read_packet)
yading@11:                     return AVERROR(EIO);
yading@11:                 goto recover;
yading@11:             }
yading@11: 
yading@11:             avio_read(pb, pes_header_data, pes_header_data_length);
yading@11:             length -= 9 + pes_header_data_length;
yading@11: 
yading@11:             pes_packet_length -= 3 + pes_header_data_length;
yading@11: 
yading@11:             pvactx->continue_pes = pes_packet_length;
yading@11: 
yading@11:             if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20)
yading@11:                 pva_pts = ff_parse_pes_pts(pes_header_data);
yading@11:         }
yading@11: 
yading@11:         pvactx->continue_pes -= length;
yading@11: 
yading@11:         if (pvactx->continue_pes < 0) {
yading@11:             pva_log(s, AV_LOG_WARNING, "audio data corruption\n");
yading@11:             pvactx->continue_pes = 0;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     if (pva_pts != AV_NOPTS_VALUE)
yading@11:         av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME);
yading@11: 
yading@11:     *pts   = pva_pts;
yading@11:     *len   = length;
yading@11:     *strid = streamid;
yading@11:     return 0;
yading@11: }
yading@11: 
yading@11: static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     int64_t pva_pts;
yading@11:     int ret, length, streamid;
yading@11: 
yading@11:     if (read_part_of_packet(s, &pva_pts, &length, &streamid, 1) < 0 ||
yading@11:        (ret = av_get_packet(pb, pkt, length)) <= 0)
yading@11:         return AVERROR(EIO);
yading@11: 
yading@11:     pkt->stream_index = streamid - 1;
yading@11:     pkt->pts = pva_pts;
yading@11: 
yading@11:     return ret;
yading@11: }
yading@11: 
yading@11: static int64_t pva_read_timestamp(struct AVFormatContext *s, int stream_index,
yading@11:                                           int64_t *pos, int64_t pos_limit) {
yading@11:     AVIOContext *pb = s->pb;
yading@11:     PVAContext *pvactx = s->priv_data;
yading@11:     int length, streamid;
yading@11:     int64_t res = AV_NOPTS_VALUE;
yading@11: 
yading@11:     pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit);
yading@11: 
yading@11:     while (*pos < pos_limit) {
yading@11:         res = AV_NOPTS_VALUE;
yading@11:         avio_seek(pb, *pos, SEEK_SET);
yading@11: 
yading@11:         pvactx->continue_pes = 0;
yading@11:         if (read_part_of_packet(s, &res, &length, &streamid, 0)) {
yading@11:             (*pos)++;
yading@11:             continue;
yading@11:         }
yading@11:         if (streamid - 1 != stream_index || res == AV_NOPTS_VALUE) {
yading@11:             *pos = avio_tell(pb) + length;
yading@11:             continue;
yading@11:         }
yading@11:         break;
yading@11:     }
yading@11: 
yading@11:     pvactx->continue_pes = 0;
yading@11:     return res;
yading@11: }
yading@11: 
yading@11: AVInputFormat ff_pva_demuxer = {
yading@11:     .name           = "pva",
yading@11:     .long_name      = NULL_IF_CONFIG_SMALL("TechnoTrend PVA"),
yading@11:     .priv_data_size = sizeof(PVAContext),
yading@11:     .read_probe     = pva_probe,
yading@11:     .read_header    = pva_read_header,
yading@11:     .read_packet    = pva_read_packet,
yading@11:     .read_timestamp = pva_read_timestamp,
yading@11: };