Bethsoft VID demuxer and video decoder

patch by Nicholas Tung, ntung ntung com

Originally committed as revision 8649 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 234 insertions, 0 deletions

diff --git a/libavformat/bethsoftvid.c b/libavformat/bethsoftvid.c
new file mode 100644
index 0000000000..7ea483505d
--- /dev/null
+++ b/libavformat/bethsoftvid.c
@@ -0,0 +1,234 @@
+/*
+ * Bethsoft VID format Demuxer
+ * Copyright (c) 2007 Nicholas Tung
+ *
+ * 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
+ */
+
+/**
+ * @file bethsoftvid.c
+ * @brief Bethesda Softworks VID (.vid) file demuxer
+ * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
+ * @sa http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
+ * @sa http://www.svatopluk.com/andux/docs/dfvid.html
+ */
+
+#include "avformat.h"
+#include "bethsoftvideo.h"
+
+typedef struct BVID_DemuxContext
+{
+    int nframes;
+    /** delay value between frames, added to individual frame delay.
+     * custom units, which will be added to other custom units (~=16ms according
+     * to free, unofficial documentation) */
+    int bethsoft_global_delay;
+
+    /** video presentation time stamp.
+     * delay = 16 milliseconds * (global_delay + per_frame_delay) */
+    int64_t video_pts;
+
+    int is_finished;
+
+} BVID_DemuxContext;
+
+static int vid_probe(AVProbeData *p)
+{
+    // little endian VID tag, file starts with "VID\0"
+    if (p->buf_size < 4 || AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
+        return 0;
+
+    return AVPROBE_SCORE_MAX;
+}
+
+static int vid_read_header(AVFormatContext *s,
+                            AVFormatParameters *ap)
+{
+    BVID_DemuxContext *vid = s->priv_data;     // permanent data outside of function
+    ByteIOContext *pb = &s->pb;                // io to file
+    AVStream *stream;
+
+    /* load main header. Contents:
+    *    bytes: 'V' 'I' 'D'
+    *    int16s: always_512, nframes, width, height, delay, always_14
+    */
+    url_fseek(pb, 5, SEEK_CUR);
+    vid->nframes = get_le16(pb);
+
+    // FFmpeg central code will use this; don't need to return or anything
+    // initialize the bethsoft codec
+    stream = av_new_stream(s, 0);
+    if (!stream) { return AVERROR_NOMEM; }
+    av_set_pts_info(stream, 32, 1, 60);     // 16 ms increments, i.e. 60 fps
+    stream->codec->codec_type = CODEC_TYPE_VIDEO;
+    stream->codec->codec_id = CODEC_ID_BETHSOFTVID;
+    stream->codec->width = get_le16(pb);
+    stream->codec->height = get_le16(pb);
+    stream->codec->pix_fmt = PIX_FMT_PAL8;
+    vid->bethsoft_global_delay = get_le16(pb);
+    get_le16(pb);
+
+    // done with video codec, set up audio codec
+    stream = av_new_stream(s, 0);
+    if (!stream) { return AVERROR_NOMEM; }
+    stream->codec->codec_type = CODEC_TYPE_AUDIO;
+    stream->codec->codec_id = CODEC_ID_PCM_U8;
+    stream->codec->channels = 1;
+    stream->codec->sample_rate = 11025;
+    stream->codec->bits_per_sample = 8;
+    stream->codec->bit_rate = stream->codec->channels * stream->codec->sample_rate * stream->codec->bits_per_sample;
+
+    return 0;
+}
+
+#define BUFFER_PADDING_SIZE 1000
+static int read_frame(BVID_DemuxContext *vid, ByteIOContext *pb, AVPacket *pkt,
+                      uint8_t block_type, AVFormatContext *s, int npixels)
+{
+    uint8_t * vidbuf_start = NULL;
+    int vidbuf_nbytes = 0;
+    int rle_num_bytes;
+    int bytes_copied = 0;
+    int position;
+    size_t vidbuf_capacity;
+
+    vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
+    if(!vidbuf_start) { return AVERROR_NOMEM; }
+
+    // save the file position for the packet, include block type
+    position = url_ftell(pb) - 1;
+
+    // set the block type for the decoder
+    vidbuf_start[vidbuf_nbytes++] = block_type;
+
+    // get the video delay (next int16), and set the presentation time
+    vid->video_pts += vid->bethsoft_global_delay + get_le16(pb);
+
+    // set the y offset if it exists (decoder header data should be in data section)
+    if(block_type == VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK)
+    {
+        if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) { return AVERROR_IO; }
+        vidbuf_nbytes += 2;
+    }
+
+    do
+    {
+        vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
+        if(!vidbuf_start) { return AVERROR_NOMEM; }
+
+        rle_num_bytes = get_byte(pb);
+        vidbuf_start[vidbuf_nbytes++] = rle_num_bytes;
+
+        if(rle_num_bytes > 0x80) // rle sequence
+        {
+            if(block_type == VIDEO_FULL_FRAME_BLOCK) { vidbuf_start[vidbuf_nbytes++] = get_byte(pb); }
+            bytes_copied += rle_num_bytes - 0x80;
+        }
+        else if(rle_num_bytes) // plain sequence
+        {
+            if(get_buffer(pb, &vidbuf_start[vidbuf_nbytes], rle_num_bytes) != rle_num_bytes)
+                return AVERROR_IO;
+            vidbuf_nbytes += rle_num_bytes;
+            bytes_copied += rle_num_bytes;
+        }
+        if(bytes_copied == npixels) // sometimes no stop character is given, need to keep track of bytes copied
+        {
+            // may contain a 0 byte even if read all pixels
+            if(get_byte(pb)) { url_fseek(pb, -1, SEEK_CUR); }
+            break;
+        }
+        if(bytes_copied > npixels) { return -1; }    // error
+    } while(rle_num_bytes);
+
+    // copy data into packet
+    if(av_new_packet(pkt, vidbuf_nbytes)) { return AVERROR_NOMEM; }
+    memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
+    av_free(vidbuf_start);
+
+    pkt->pos = position;
+    pkt->stream_index = 0;  // use the video decoder, which was initialized as the first stream
+    pkt->pts = vid->video_pts;
+
+    vid->nframes--;  // used to check if all the frames were read
+    return vidbuf_nbytes;
+}
+
+static int vid_read_packet(AVFormatContext *s,
+                           AVPacket *pkt)
+{
+    BVID_DemuxContext *vid = s->priv_data;     // permanent data outside of function
+    ByteIOContext *pb = &s->pb;                // io to file
+    unsigned char block_type;                  // block type
+    int audio_length;
+    int ret_value;
+
+    av_log(s, AV_LOG_DEBUG, "[bethsoftvid demuxer read_packet]");
+
+    if(vid->is_finished || url_feof(pb)) { return AVERROR_IO; }
+
+    block_type = get_byte(pb);
+    switch(block_type)
+    {
+        case PALETTE_BLOCK:
+            av_log(s, AV_LOG_DEBUG, "palette block.\n");
+            url_fseek(pb, -1, SEEK_CUR);     // include block type
+            ret_value = av_get_packet(pb, pkt, 3 * VID_PALETTE_NUMCOLORS + 1);
+            if(ret_value != 3 * VID_PALETTE_NUMCOLORS + 1) { av_free_packet(pkt); return AVERROR_IO; }
+            pkt->stream_index = 0;
+            return ret_value;
+
+        case FIRST_AUDIO_BLOCK:
+            av_log(s, AV_LOG_DEBUG, "first ");
+            get_le16(pb); //    some unused constant
+            // soundblaster DAC used for sample rate, as on specification page (link above)
+            s->streams[1]->codec->sample_rate = 1000000 / (256 - get_byte(pb));
+            s->streams[1]->codec->bit_rate = s->streams[1]->codec->channels * s->streams[1]->codec->sample_rate * s->streams[1]->codec->bits_per_sample;
+        case AUDIO_BLOCK:
+            av_log(s, AV_LOG_DEBUG, "audio block.\n");
+            audio_length = get_le16(pb);
+            ret_value = av_get_packet(pb, pkt, audio_length);
+            pkt->stream_index = 1;
+            return (ret_value != audio_length ? AVERROR_IO : ret_value);
+
+        case VIDEO_DIFFERENCE_FRAME_BLOCK: av_log(s, AV_LOG_DEBUG, "non-");
+        case VIDEO_YOFFSET_DIFFERENCE_FRAME_BLOCK: av_log(s, AV_LOG_DEBUG, "offset ");
+        case VIDEO_FULL_FRAME_BLOCK: av_log(s, AV_LOG_DEBUG, "video block.\n");
+            return read_frame(vid, pb, pkt, block_type, s,
+                              s->streams[0]->codec->width * s->streams[0]->codec->height);
+
+        case FINISHED_BLOCK:
+            if(vid->nframes != 0)
+                av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
+            vid->is_finished = 1;
+            av_log(s, AV_LOG_DEBUG, "terminating block.\n");
+            return AVERROR_IO;
+        default:
+            av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
+                   block_type, block_type, block_type); return -1;
+    }
+
+    return 0;
+}
+
+AVInputFormat bethsoftvid_demuxer = {
+    "bethsoftvid",
+    "Bethesda Softworks 'Daggerfall' VID format",
+    sizeof(BVID_DemuxContext),
+    vid_probe,
+    vid_read_header,
+    vid_read_packet,
+};