diff ffmpeg/libavformat/pva.c @ 11:f445c3017523

new files

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ffmpeg/libavformat/pva.c	Sun Apr 21 11:16:23 2013 +0200
@@ -0,0 +1,225 @@
+/*
+ * 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 {
+    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(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_MAX / 2;
+
+    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->codec->codec_type = AVMEDIA_TYPE_VIDEO;
+    st->codec->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->codec->codec_type = AVMEDIA_TYPE_AUDIO;
+    st->codec->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,
+};