| /* |
| * TechnoTrend PVA (.pva) demuxer |
| * Copyright (c) 2007, 2008 Ivo van Poorten |
| * |
| * 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 "avformat.h" |
| #include "internal.h" |
| #include "mpeg.h" |
| |
| #define PVA_MAX_PAYLOAD_LENGTH 0x17f8 |
| #define PVA_VIDEO_PAYLOAD 0x01 |
| #define PVA_AUDIO_PAYLOAD 0x02 |
| #define PVA_MAGIC (('A' << 8) + 'V') |
| |
| typedef struct PVAContext { |
| int continue_pes; |
| } PVAContext; |
| |
| static int pva_check(const uint8_t *p) { |
| int length = AV_RB16(p + 6); |
| if (AV_RB16(p) != PVA_MAGIC || !p[2] || p[2] > 2 || p[4] != 0x55 || |
| (p[5] & 0xe0) || length > PVA_MAX_PAYLOAD_LENGTH) |
| return -1; |
| return length + 8; |
| } |
| |
| static int pva_probe(const AVProbeData * pd) { |
| const unsigned char *buf = pd->buf; |
| int len = pva_check(buf); |
| |
| if (len < 0) |
| return 0; |
| |
| if (pd->buf_size >= len + 8 && |
| pva_check(buf + len) >= 0) |
| return AVPROBE_SCORE_EXTENSION; |
| |
| return AVPROBE_SCORE_MAX / 4; |
| } |
| |
| static int pva_read_header(AVFormatContext *s) { |
| AVStream *st; |
| |
| if (!(st = avformat_new_stream(s, NULL))) |
| return AVERROR(ENOMEM); |
| st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
| st->codecpar->codec_id = AV_CODEC_ID_MPEG2VIDEO; |
| st->need_parsing = AVSTREAM_PARSE_FULL; |
| avpriv_set_pts_info(st, 32, 1, 90000); |
| av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); |
| |
| if (!(st = avformat_new_stream(s, NULL))) |
| return AVERROR(ENOMEM); |
| st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
| st->codecpar->codec_id = AV_CODEC_ID_MP2; |
| st->need_parsing = AVSTREAM_PARSE_FULL; |
| avpriv_set_pts_info(st, 33, 1, 90000); |
| av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); |
| |
| /* the parameters will be extracted from the compressed bitstream */ |
| return 0; |
| } |
| |
| #define pva_log if (read_packet) av_log |
| |
| static int read_part_of_packet(AVFormatContext *s, int64_t *pts, |
| int *len, int *strid, int read_packet) { |
| AVIOContext *pb = s->pb; |
| PVAContext *pvactx = s->priv_data; |
| int syncword, streamid, reserved, flags, length, pts_flag; |
| int64_t pva_pts = AV_NOPTS_VALUE, startpos; |
| int ret; |
| |
| recover: |
| startpos = avio_tell(pb); |
| |
| syncword = avio_rb16(pb); |
| streamid = avio_r8(pb); |
| avio_r8(pb); /* counter not used */ |
| reserved = avio_r8(pb); |
| flags = avio_r8(pb); |
| length = avio_rb16(pb); |
| |
| pts_flag = flags & 0x10; |
| |
| if (syncword != PVA_MAGIC) { |
| pva_log(s, AV_LOG_ERROR, "invalid syncword\n"); |
| return AVERROR(EIO); |
| } |
| if (streamid != PVA_VIDEO_PAYLOAD && streamid != PVA_AUDIO_PAYLOAD) { |
| pva_log(s, AV_LOG_ERROR, "invalid streamid\n"); |
| return AVERROR(EIO); |
| } |
| if (reserved != 0x55) { |
| pva_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n"); |
| } |
| if (length > PVA_MAX_PAYLOAD_LENGTH) { |
| pva_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length); |
| return AVERROR(EIO); |
| } |
| |
| if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) { |
| pva_pts = avio_rb32(pb); |
| length -= 4; |
| } else if (streamid == PVA_AUDIO_PAYLOAD) { |
| /* PVA Audio Packets either start with a signaled PES packet or |
| * are a continuation of the previous PES packet. New PES packets |
| * always start at the beginning of a PVA Packet, never somewhere in |
| * the middle. */ |
| if (!pvactx->continue_pes) { |
| int pes_signal, pes_header_data_length, pes_packet_length, |
| pes_flags; |
| unsigned char pes_header_data[256]; |
| |
| pes_signal = avio_rb24(pb); |
| avio_r8(pb); |
| pes_packet_length = avio_rb16(pb); |
| pes_flags = avio_rb16(pb); |
| pes_header_data_length = avio_r8(pb); |
| |
| if (avio_feof(pb)) { |
| return AVERROR_EOF; |
| } |
| |
| if (pes_signal != 1 || pes_header_data_length == 0) { |
| pva_log(s, AV_LOG_WARNING, "expected non empty signaled PES packet, " |
| "trying to recover\n"); |
| avio_skip(pb, length - 9); |
| if (!read_packet) |
| return AVERROR(EIO); |
| goto recover; |
| } |
| |
| ret = avio_read(pb, pes_header_data, pes_header_data_length); |
| if (ret != pes_header_data_length) |
| return ret < 0 ? ret : AVERROR_INVALIDDATA; |
| length -= 9 + pes_header_data_length; |
| |
| pes_packet_length -= 3 + pes_header_data_length; |
| |
| pvactx->continue_pes = pes_packet_length; |
| |
| if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20) { |
| if (pes_header_data_length < 5) { |
| pva_log(s, AV_LOG_ERROR, "header too short\n"); |
| avio_skip(pb, length); |
| return AVERROR_INVALIDDATA; |
| } |
| pva_pts = ff_parse_pes_pts(pes_header_data); |
| } |
| } |
| |
| pvactx->continue_pes -= length; |
| |
| if (pvactx->continue_pes < 0) { |
| pva_log(s, AV_LOG_WARNING, "audio data corruption\n"); |
| pvactx->continue_pes = 0; |
| } |
| } |
| |
| if (pva_pts != AV_NOPTS_VALUE) |
| av_add_index_entry(s->streams[streamid-1], startpos, pva_pts, 0, 0, AVINDEX_KEYFRAME); |
| |
| *pts = pva_pts; |
| *len = length; |
| *strid = streamid; |
| return 0; |
| } |
| |
| static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) { |
| AVIOContext *pb = s->pb; |
| int64_t pva_pts; |
| int ret, length, streamid; |
| |
| if (read_part_of_packet(s, &pva_pts, &length, &streamid, 1) < 0 || |
| (ret = av_get_packet(pb, pkt, length)) <= 0) |
| return AVERROR(EIO); |
| |
| pkt->stream_index = streamid - 1; |
| pkt->pts = pva_pts; |
| |
| return ret; |
| } |
| |
| static int64_t pva_read_timestamp(struct AVFormatContext *s, int stream_index, |
| int64_t *pos, int64_t pos_limit) { |
| AVIOContext *pb = s->pb; |
| PVAContext *pvactx = s->priv_data; |
| int length, streamid; |
| int64_t res = AV_NOPTS_VALUE; |
| |
| pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit); |
| |
| while (*pos < pos_limit) { |
| res = AV_NOPTS_VALUE; |
| avio_seek(pb, *pos, SEEK_SET); |
| |
| pvactx->continue_pes = 0; |
| if (read_part_of_packet(s, &res, &length, &streamid, 0)) { |
| (*pos)++; |
| continue; |
| } |
| if (streamid - 1 != stream_index || res == AV_NOPTS_VALUE) { |
| *pos = avio_tell(pb) + length; |
| continue; |
| } |
| break; |
| } |
| |
| pvactx->continue_pes = 0; |
| return res; |
| } |
| |
| AVInputFormat ff_pva_demuxer = { |
| .name = "pva", |
| .long_name = NULL_IF_CONFIG_SMALL("TechnoTrend PVA"), |
| .priv_data_size = sizeof(PVAContext), |
| .read_probe = pva_probe, |
| .read_header = pva_read_header, |
| .read_packet = pva_read_packet, |
| .read_timestamp = pva_read_timestamp, |
| }; |
