/* * TechnoTrend PVA (.pva) demuxer * Copyright (c) 2007, 2008 Ivo van Poorten * * 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 */ #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_probe(AVProbeData * pd) { unsigned char *buf = pd->buf; if (AV_RB16(buf) == PVA_MAGIC && buf[2] && buf[2] < 3 && buf[4] == 0x55) return AVPROBE_SCORE_EXTENSION; return 0; } 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; 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 (pes_signal != 1) { pva_log(s, AV_LOG_WARNING, "expected signaled PES packet, " "trying to recover\n"); avio_skip(pb, length - 9); if (!read_packet) return AVERROR(EIO); goto recover; } avio_read(pb, pes_header_data, pes_header_data_length); 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) 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, };