[SCM] libav/experimental: TechnoTrend PVA Demuxer

siretart at users.alioth.debian.org siretart at users.alioth.debian.org
Sun Jun 30 16:11:06 UTC 2013


The following commit has been merged in the experimental branch:
commit 3feb44a9bee71e3a0e681cd401d4c28d623a4298
Author: Ivo van Poorten <ivop at euronet.nl>
Date:   Wed Jan 2 10:45:28 2008 +0000

    TechnoTrend PVA Demuxer
    
    Originally committed as revision 11371 to svn://svn.ffmpeg.org/ffmpeg/trunk

diff --git a/libavformat/Makefile b/libavformat/Makefile
index 69c73e5..4d2094a 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -113,6 +113,7 @@ OBJS-$(CONFIG_OGG_DEMUXER)               += oggdec.o         \
                                             riff.o
 OBJS-$(CONFIG_OGG_MUXER)                 += oggenc.o
 OBJS-$(CONFIG_PSP_MUXER)                 += movenc.o riff.o isom.o
+OBJS-$(CONFIG_PVA_DEMUXER)               += pva.o
 OBJS-$(CONFIG_RAWVIDEO_DEMUXER)          += raw.o
 OBJS-$(CONFIG_RAWVIDEO_MUXER)            += raw.o
 OBJS-$(CONFIG_REDIR_DEMUXER)             += rtsp.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index b663b31..611cde8 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -129,6 +129,7 @@ void av_register_all(void)
     REGISTER_MUXDEMUX (PCM_U16LE, pcm_u16le);
     REGISTER_MUXDEMUX (PCM_U8,    pcm_u8);
     REGISTER_MUXER    (PSP, psp);
+    REGISTER_DEMUXER  (PVA, pva);
     REGISTER_MUXDEMUX (RAWVIDEO, rawvideo);
     REGISTER_MUXDEMUX (RM, rm);
     REGISTER_MUXDEMUX (ROQ, roq);
diff --git a/libavformat/pva.c b/libavformat/pva.c
new file mode 100644
index 0000000..dd07497
--- /dev/null
+++ b/libavformat/pva.c
@@ -0,0 +1,153 @@
+/*
+ * 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"
+
+#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);
+
+    if (!(st = av_new_stream(s, 1)))
+        return AVERROR(ENOMEM);
+    st->codec->codec_type = CODEC_TYPE_AUDIO;
+    st->codec->codec_id   = CODEC_ID_MP3;
+    st->need_parsing      = AVSTREAM_PARSE_HEADERS;
+    av_set_pts_info(st, 33, 1, 90000);
+
+    /* the parameters will be extracted from the compressed bitstream */
+    return 0;
+}
+
+static int pva_read_packet(AVFormatContext *s, AVPacket *pkt) {
+    ByteIOContext *pb = s->pb;
+    PVAContext *pvactx = s->priv_data;
+    int ret, syncword, streamid, reserved, flags, length, pts_flag;
+    long long pva_pts = 0;
+
+    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) >> 4;
+
+    if (syncword != PVA_MAGIC) {
+        av_log(s, AV_LOG_ERROR, "invalid syncword\n");
+        return AVERROR(EIO);
+    }
+    if (reserved != 0x55) {
+        av_log(s, AV_LOG_WARNING, "expected reserved byte to be 0x55\n");
+    }
+    if (length > PVA_MAX_PAYLOAD_LENGTH) {
+        av_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) {
+                av_log(s, AV_LOG_ERROR, "expected signaled PES packet\n");
+                return AVERROR(EIO);
+            }
+
+            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  = ((long long) *pes_header_data & 0x0e) << 29;
+                pva_pts += (AV_RB16(pes_header_data+1) >> 1) << 15;
+                pva_pts +=  AV_RB16(pes_header_data+3) >> 1;
+            }
+        }
+
+        pvactx->continue_pes -= length;
+
+        if (pvactx->continue_pes < 0) {
+            av_log(s, AV_LOG_WARNING, "audio data corruption\n");
+            pvactx->continue_pes = 0;
+        }
+    }
+
+    if ((ret = av_get_packet(pb, pkt, length)) <= 0)
+        return AVERROR(EIO);
+
+    pkt->stream_index = streamid - 1;
+    if (pva_pts)
+        pkt->pts = pva_pts;
+
+    return ret;
+}
+
+AVInputFormat pva_demuxer = {
+    "pva",
+    "pva file and stream format",
+    sizeof(PVAContext),
+    pva_probe,
+    pva_read_header,
+    pva_read_packet,
+};

-- 
Libav/FFmpeg packaging



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