mirror of https://github.com/FFmpeg/FFmpeg.git
Originally committed as revision 11371 to svn://svn.ffmpeg.org/ffmpeg/trunkpull/126/head
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/*
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* TechnoTrend PVA (.pva) demuxer |
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* Copyright (c) 2007, 2008 Ivo van Poorten |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "avformat.h" |
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#define PVA_MAX_PAYLOAD_LENGTH 0x17f8 |
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#define PVA_VIDEO_PAYLOAD 0x01 |
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#define PVA_AUDIO_PAYLOAD 0x02 |
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#define PVA_MAGIC (('A' << 8) + 'V') |
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typedef struct { |
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int continue_pes; |
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} PVAContext; |
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static int pva_probe(AVProbeData * pd) { |
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unsigned char *buf = pd->buf; |
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if (AV_RB16(buf) == PVA_MAGIC && buf[2] && buf[2] < 3 && buf[4] == 0x55) |
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return AVPROBE_SCORE_MAX / 2; |
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return 0; |
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} |
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static int pva_read_header(AVFormatContext *s, AVFormatParameters *ap) { |
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AVStream *st; |
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if (!(st = av_new_stream(s, 0))) |
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return AVERROR(ENOMEM); |
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st->codec->codec_type = CODEC_TYPE_VIDEO; |
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st->codec->codec_id = CODEC_ID_MPEG2VIDEO; |
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st->need_parsing = AVSTREAM_PARSE_FULL; |
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av_set_pts_info(st, 32, 1, 90000); |
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if (!(st = av_new_stream(s, 1))) |
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return AVERROR(ENOMEM); |
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st->codec->codec_type = CODEC_TYPE_AUDIO; |
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st->codec->codec_id = CODEC_ID_MP3; |
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st->need_parsing = AVSTREAM_PARSE_HEADERS; |
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av_set_pts_info(st, 33, 1, 90000); |
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/* the parameters will be extracted from the compressed bitstream */ |
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return 0; |
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} |
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static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) { |
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ByteIOContext *pb = s->pb; |
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PVAContext *pvactx = s->priv_data; |
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int ret, syncword, streamid, reserved, flags, length, pts_flag; |
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long long pva_pts = 0; |
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syncword = get_be16(pb); |
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streamid = get_byte(pb); |
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get_byte(pb); /* counter not used */ |
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reserved = get_byte(pb); |
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flags = get_byte(pb); |
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length = get_be16(pb); |
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pts_flag = (flags & 0x10) >> 4; |
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if (syncword != PVA_MAGIC) { |
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av_log(s, AV_LOG_ERROR, "invalid syncword\n"); |
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return AVERROR(EIO); |
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} |
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if (reserved != 0x55) { |
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av_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n"); |
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} |
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if (length > PVA_MAX_PAYLOAD_LENGTH) { |
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av_log(s, AV_LOG_ERROR, "invalid payload length %u\n", length); |
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return AVERROR(EIO); |
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} |
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if (streamid == PVA_VIDEO_PAYLOAD && pts_flag) { |
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pva_pts = get_be32(pb); |
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length -= 4; |
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} else if (streamid == PVA_AUDIO_PAYLOAD) { |
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/* PVA Audio Packets either start with a signaled PES packet or
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* are a continuation of the previous PES packet. New PES packets |
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* always start at the beginning of a PVA Packet, never somewhere in |
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* the middle. */ |
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if (!pvactx->continue_pes) { |
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int pes_signal, pes_header_data_length, pes_packet_length, |
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pes_flags; |
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unsigned char pes_header_data[256]; |
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pes_signal = get_be24(pb); |
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get_byte(pb); |
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pes_packet_length = get_be16(pb); |
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pes_flags = get_be16(pb); |
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pes_header_data_length = get_byte(pb); |
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if (pes_signal != 1) { |
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av_log(s, AV_LOG_ERROR, "expected signaled PES packet\n"); |
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return AVERROR(EIO); |
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} |
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get_buffer(pb, pes_header_data, pes_header_data_length); |
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length -= 9 + pes_header_data_length; |
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pes_packet_length -= 3 + pes_header_data_length; |
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pvactx->continue_pes = pes_packet_length; |
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if (pes_flags & 0x80 && (pes_header_data[0] & 0xf0) == 0x20) { |
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pva_pts = ((long long) *pes_header_data & 0x0e) << 29; |
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pva_pts += (AV_RB16(pes_header_data+1) >> 1) << 15; |
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pva_pts += AV_RB16(pes_header_data+3) >> 1; |
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} |
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} |
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pvactx->continue_pes -= length; |
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if (pvactx->continue_pes < 0) { |
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av_log(s, AV_LOG_WARNING, "audio data corruption\n"); |
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pvactx->continue_pes = 0; |
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} |
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} |
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if ((ret = av_get_packet(pb, pkt, length)) <= 0) |
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return AVERROR(EIO); |
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pkt->stream_index = streamid - 1; |
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if (pva_pts) |
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pkt->pts = pva_pts; |
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return ret; |
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} |
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AVInputFormat pva_demuxer = { |
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"pva", |
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"pva file and stream format", |
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sizeof(PVAContext), |
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pva_probe, |
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pva_read_header, |
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pva_read_packet, |
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}; |
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