diff options
Diffstat (limited to 'contrib/ffmpeg/libavformat/pva.c')
| -rw-r--r-- | contrib/ffmpeg/libavformat/pva.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavformat/pva.c b/contrib/ffmpeg/libavformat/pva.c new file mode 100644 index 000000000..03b92bf3d --- /dev/null +++ b/contrib/ffmpeg/libavformat/pva.c @@ -0,0 +1,211 @@ +/* + * 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 "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 { + 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_MAX / 2; + + return 0; +} + +static int pva_read_header(AVFormatContext *s, AVFormatParameters *ap) { + AVStream *st; + + if (!(st = av_new_stream(s, 0))) + return AVERROR(ENOMEM); + st->codec->codec_type = CODEC_TYPE_VIDEO; + st->codec->codec_id = CODEC_ID_MPEG2VIDEO; + st->need_parsing = AVSTREAM_PARSE_FULL; + av_set_pts_info(st, 32, 1, 90000); + av_add_index_entry(st, 0, 0, 0, 0, AVINDEX_KEYFRAME); + + if (!(st = av_new_stream(s, 1))) + return AVERROR(ENOMEM); + st->codec->codec_type = CODEC_TYPE_AUDIO; + st->codec->codec_id = CODEC_ID_MP2; + st->need_parsing = AVSTREAM_PARSE_HEADERS; + av_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) { + ByteIOContext *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 = url_ftell(pb); + + syncword = get_be16(pb); + streamid = get_byte(pb); + get_byte(pb); /* counter not used */ + reserved = get_byte(pb); + flags = get_byte(pb); + length = get_be16(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 = get_be32(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 = get_be24(pb); + get_byte(pb); + pes_packet_length = get_be16(pb); + pes_flags = get_be16(pb); + pes_header_data_length = get_byte(pb); + + if (pes_signal != 1) { + pva_log(s, AV_LOG_WARNING, "expected signaled PES packet, " + "trying to recover\n"); + url_fskip(pb, length - 9); + if (!read_packet) + return AVERROR(EIO); + goto recover; + } + + get_buffer(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) { + ByteIOContext *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) { + ByteIOContext *pb = s->pb; + PVAContext *pvactx = s->priv_data; + int length, streamid; + int64_t res; + + pos_limit = FFMIN(*pos+PVA_MAX_PAYLOAD_LENGTH*8, (uint64_t)*pos+pos_limit); + + while (*pos < pos_limit) { + res = AV_NOPTS_VALUE; + url_fseek(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 = url_ftell(pb) + length; + continue; + } + break; + } + + pvactx->continue_pes = 0; + return res; +} + +AVInputFormat pva_demuxer = { + "pva", + "pva file and stream format", + sizeof(PVAContext), + pva_probe, + pva_read_header, + pva_read_packet, + .read_timestamp = pva_read_timestamp +}; |