ffmpeg-2.8.5

git-svn-id: svn://kolibrios.org@6147 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/ffmpeg/ffmpeg-2.8/libavformat/lmlm4.c

@@ -0,0 +1,130 @@
+/*
+ * Linux Media Labs MPEG-4 demuxer
+ * Copyright (c) 2008 Ivo van Poorten
+ *
+ * Due to a lack of sample files, only files with one channel are supported.
+ * u-law and ADPCM audio are unsupported for the same reason.
+ *
+ * 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 "libavutil/intreadwrite.h"
+
+#include "avformat.h"
+#include "internal.h"
+
+#define LMLM4_I_FRAME   0x00
+#define LMLM4_P_FRAME   0x01
+#define LMLM4_B_FRAME   0x02
+#define LMLM4_INVALID   0x03
+#define LMLM4_MPEG1L2   0x04
+
+#define LMLM4_MAX_PACKET_SIZE   1024 * 1024
+
+static int lmlm4_probe(AVProbeData *pd)
+{
+    const unsigned char *buf = pd->buf;
+    unsigned int frame_type, packet_size;
+
+    frame_type  = AV_RB16(buf + 2);
+    packet_size = AV_RB32(buf + 4);
+
+    if (!AV_RB16(buf) && frame_type <= LMLM4_MPEG1L2 && packet_size &&
+        frame_type != LMLM4_INVALID && packet_size <= LMLM4_MAX_PACKET_SIZE) {
+        if (frame_type == LMLM4_MPEG1L2) {
+            if ((AV_RB16(buf + 8) & 0xfffe) != 0xfffc)
+                return 0;
+            /* I could calculate the audio framesize and compare with
+             * packet_size-8, but that seems overkill */
+            return AVPROBE_SCORE_MAX / 3;
+        } else if (AV_RB24(buf + 8) == 0x000001) {    /* PES Signal */
+            return AVPROBE_SCORE_MAX / 5;
+        }
+    }
+
+    return 0;
+}
+
+static int lmlm4_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_MPEG4;
+    st->need_parsing      = AVSTREAM_PARSE_HEADERS;
+    avpriv_set_pts_info(st, 64, 1001, 30000);
+
+    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_HEADERS;
+
+    /* the parameters will be extracted from the compressed bitstream */
+    return 0;
+}
+
+static int lmlm4_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    AVIOContext *pb = s->pb;
+    int ret;
+    unsigned int frame_type, packet_size, padding, frame_size;
+
+    avio_rb16(pb);                       /* channel number */
+    frame_type  = avio_rb16(pb);
+    packet_size = avio_rb32(pb);
+    padding     = -packet_size & 511;
+    frame_size  = packet_size - 8;
+
+    if (frame_type > LMLM4_MPEG1L2 || frame_type == LMLM4_INVALID) {
+        av_log(s, AV_LOG_ERROR, "invalid or unsupported frame_type\n");
+        return AVERROR(EIO);
+    }
+    if (packet_size > LMLM4_MAX_PACKET_SIZE || packet_size<=8) {
+        av_log(s, AV_LOG_ERROR, "packet size %d is invalid\n", packet_size);
+        return AVERROR(EIO);
+    }
+
+    if ((ret = av_get_packet(pb, pkt, frame_size)) <= 0)
+        return AVERROR(EIO);
+
+    avio_skip(pb, padding);
+
+    switch (frame_type) {
+    case LMLM4_I_FRAME:
+        pkt->flags = AV_PKT_FLAG_KEY;
+    case LMLM4_P_FRAME:
+    case LMLM4_B_FRAME:
+        pkt->stream_index = 0;
+        break;
+    case LMLM4_MPEG1L2:
+        pkt->stream_index = 1;
+        break;
+    }
+
+    return ret;
+}
+
+AVInputFormat ff_lmlm4_demuxer = {
+    .name           = "lmlm4",
+    .long_name      = NULL_IF_CONFIG_SMALL("raw lmlm4"),
+    .read_probe     = lmlm4_probe,
+    .read_header    = lmlm4_read_header,
+    .read_packet    = lmlm4_read_packet,
+};