Add 8088flex TMV file demuxer.

Patch by Daniel Verkamp daniel|at|drv|nu.

Originally committed as revision 18766 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 156 insertions, 0 deletions

diff --git a/libavformat/tmv.c b/libavformat/tmv.c
new file mode 100644
index 0000000000..566f562810
--- /dev/null
+++ b/libavformat/tmv.c
@@ -0,0 +1,156 @@
+/*
+ * 8088flex TMV file demuxer
+ * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
+ *
+ * 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
+ */
+
+/**
+ * 8088flex TMV file demuxer
+ * @file libavformat/tmv.c
+ * @author Daniel Verkamp
+ * @sa http://www.oldskool.org/pc/8088_Corruption
+ */
+
+#include "libavutil/intreadwrite.h"
+#include "avformat.h"
+
+enum {
+    TMV_PADDING = 0x01,
+    TMV_STEREO  = 0x02,
+};
+
+#define TMV_TAG MKTAG('T', 'M', 'A', 'V')
+
+typedef struct TMVContext {
+    unsigned audio_chunk_size;
+    unsigned video_chunk_size;
+    unsigned padding;
+    unsigned stream_index;
+} TMVContext;
+
+static int tmv_probe(AVProbeData *p)
+{
+    if (AV_RL32(p->buf) == TMV_TAG)
+        return AVPROBE_SCORE_MAX;
+    return 0;
+}
+
+static int tmv_read_header(AVFormatContext *s, AVFormatParameters *ap)
+{
+    TMVContext *tmv   = s->priv_data;
+    ByteIOContext *pb = s->pb;
+    AVStream *vst, *ast;
+    AVRational fps;
+    unsigned comp_method, char_cols, char_rows, features;
+
+    if (get_le32(pb) != TMV_TAG)
+        return -1;
+
+    if (!(vst = av_new_stream(s, 0)))
+        return AVERROR(ENOMEM);
+
+    if (!(ast = av_new_stream(s, 0)))
+        return AVERROR(ENOMEM);
+
+    ast->codec->sample_rate = get_le16(pb);
+    tmv->audio_chunk_size   = get_le16(pb);
+    if (!tmv->audio_chunk_size) {
+        av_log(s, AV_LOG_ERROR, "invalid audio chunk size\n");
+        return -1;
+    }
+
+    comp_method             = get_byte(pb);
+    if (comp_method) {
+        av_log(s, AV_LOG_ERROR, "unsupported compression method %d\n",
+               comp_method);
+        return -1;
+    }
+
+    char_cols = get_byte(pb);
+    char_rows = get_byte(pb);
+    tmv->video_chunk_size = char_cols * char_rows * 2;
+
+    features  = get_byte(pb);
+    if (features & ~(TMV_PADDING | TMV_STEREO)) {
+        av_log(s, AV_LOG_ERROR, "unsupported features 0x%02x\n",
+               features & ~(TMV_PADDING | TMV_STEREO));
+        return -1;
+    }
+
+    ast->codec->codec_type            = CODEC_TYPE_AUDIO;
+    ast->codec->codec_id              = CODEC_ID_PCM_U8;
+    ast->codec->sample_fmt            = SAMPLE_FMT_U8;
+    ast->codec->channels              = features & TMV_STEREO ? 2 : 1;
+    ast->codec->bits_per_coded_sample = 8;
+    ast->codec->bit_rate              = ast->codec->sample_rate *
+                                        ast->codec->bits_per_coded_sample;
+    av_set_pts_info(ast, 32, 1, ast->codec->sample_rate);
+
+    fps.num = ast->codec->sample_rate * ast->codec->channels;
+    fps.den = tmv->audio_chunk_size;
+    av_reduce(&fps.num, &fps.den, fps.num, fps.den, 0xFFFFFFFFLL);
+
+    vst->codec->codec_type = CODEC_TYPE_VIDEO;
+    vst->codec->codec_id   = CODEC_ID_TMV;
+    vst->codec->pix_fmt    = PIX_FMT_PAL8;
+    vst->codec->width      = char_cols * 8;
+    vst->codec->height     = char_rows * 8;
+    av_set_pts_info(vst, 32, fps.den, fps.num);
+
+    if (features & TMV_PADDING)
+        tmv->padding =
+            ((tmv->video_chunk_size + tmv->audio_chunk_size + 511) & ~511) -
+             (tmv->video_chunk_size + tmv->audio_chunk_size);
+
+    vst->codec->bit_rate = ((tmv->video_chunk_size + tmv->padding) *
+                            fps.num * 8) / fps.den;
+
+    return 0;
+}
+
+static int tmv_read_packet(AVFormatContext *s, AVPacket *pkt)
+{
+    TMVContext *tmv   = s->priv_data;
+    ByteIOContext *pb = s->pb;
+    int ret, pkt_size = tmv->stream_index ?
+                        tmv->audio_chunk_size : tmv->video_chunk_size;
+
+    if (url_feof(pb))
+        return AVERROR_EOF;
+
+    ret = av_get_packet(pb, pkt, pkt_size);
+
+    if (tmv->stream_index)
+        url_fskip(pb, tmv->padding);
+
+    pkt->stream_index  = tmv->stream_index;
+    tmv->stream_index ^= 1;
+    pkt->flags        |= PKT_FLAG_KEY;
+
+    return ret;
+}
+
+AVInputFormat tmv_demuxer = {
+    "tmv",
+    NULL_IF_CONFIG_SMALL("8088flex TMV"),
+    sizeof(TMVContext),
+    tmv_probe,
+    tmv_read_header,
+    tmv_read_packet,
+    .flags = AVFMT_GENERIC_INDEX,
+};