Chronomaster DFA decoder

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 395 insertions, 0 deletions

diff --git a/libavcodec/dfa.c b/libavcodec/dfa.c
new file mode 100644
index 0000000000..1023197c38
--- /dev/null
+++ b/libavcodec/dfa.c
@@ -0,0 +1,395 @@
+/*
+ * Chronomaster DFA Video Decoder
+ * Copyright (c) 2011 Konstantin Shishkov
+ * based on work by Vladimir "VAG" Gneushev
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avcodec.h"
+#include "libavutil/intreadwrite.h"
+#include "bytestream.h"
+#include "libavutil/lzo.h" // for av_memcpy_backptr
+
+typedef struct DfaContext {
+    AVFrame pic;
+
+    uint32_t pal[256];
+    uint8_t *frame_buf;
+} DfaContext;
+
+static av_cold int dfa_decode_init(AVCodecContext *avctx)
+{
+    DfaContext *s = avctx->priv_data;
+
+    avctx->pix_fmt = PIX_FMT_PAL8;
+
+    s->frame_buf = av_mallocz(avctx->width * avctx->height + AV_LZO_OUTPUT_PADDING);
+    if (!s->frame_buf)
+        return AVERROR(ENOMEM);
+
+    return 0;
+}
+
+static int decode_copy(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    const int size = width * height;
+
+    if (src_end - src < size)
+        return -1;
+    bytestream_get_buffer(&src, frame, size);
+    return 0;
+}
+
+static int decode_tsw1(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    const uint8_t *frame_start = frame;
+    const uint8_t *frame_end   = frame + width * height;
+    int mask = 0x10000, bitbuf = 0;
+    int v, offset, count, segments;
+
+    segments = bytestream_get_le32(&src);
+    frame   += bytestream_get_le32(&src);
+    if (frame < frame_start || frame > frame_end)
+        return -1;
+    while (segments--) {
+        if (mask == 0x10000) {
+            if (src >= src_end)
+                return -1;
+            bitbuf = bytestream_get_le16(&src);
+            mask = 1;
+        }
+        if (src_end - src < 2 || frame_end - frame < 2)
+            return -1;
+        if (bitbuf & mask) {
+            v = bytestream_get_le16(&src);
+            offset = (v & 0x1FFF) << 1;
+            count = ((v >> 13) + 2) << 1;
+            if (frame - offset < frame_start || frame_end - frame < count)
+                return -1;
+            av_memcpy_backptr(frame, offset, count);
+            frame += count;
+        } else {
+            *frame++ = *src++;
+            *frame++ = *src++;
+        }
+        mask <<= 1;
+    }
+
+    return 0;
+}
+
+static int decode_dsw1(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    const uint8_t *frame_start = frame;
+    const uint8_t *frame_end   = frame + width * height;
+    int mask = 0x10000, bitbuf = 0;
+    int v, offset, count, segments;
+
+    segments = bytestream_get_le16(&src);
+    while (segments--) {
+        if (mask == 0x10000) {
+            if (src >= src_end)
+                return -1;
+            bitbuf = bytestream_get_le16(&src);
+            mask = 1;
+        }
+        if (src_end - src < 2 || frame_end - frame < 2)
+            return -1;
+        if (bitbuf & mask) {
+            v = bytestream_get_le16(&src);
+            offset = (v & 0x1FFF) << 1;
+            count = ((v >> 13) + 2) << 1;
+            if (frame - offset < frame_start || frame_end - frame < count)
+                return -1;
+            // can't use av_memcpy_backptr() since it can overwrite following pixels
+            for (v = 0; v < count; v++)
+                frame[v] = frame[v - offset];
+            frame += count;
+        } else if (bitbuf & (mask << 1)) {
+            frame += bytestream_get_le16(&src);
+        } else {
+            *frame++ = *src++;
+            *frame++ = *src++;
+        }
+        mask <<= 2;
+    }
+
+    return 0;
+}
+
+static int decode_dds1(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    const uint8_t *frame_start = frame;
+    const uint8_t *frame_end   = frame + width * height;
+    int mask = 0x10000, bitbuf = 0;
+    int i, v, offset, count, segments;
+
+    segments = bytestream_get_le16(&src);
+    while (segments--) {
+        if (mask == 0x10000) {
+            if (src >= src_end)
+                return -1;
+            bitbuf = bytestream_get_le16(&src);
+            mask = 1;
+        }
+        if (src_end - src < 2 || frame_end - frame < 2)
+            return -1;
+        if (bitbuf & mask) {
+            v = bytestream_get_le16(&src);
+            offset = (v & 0x1FFF) << 2;
+            count = ((v >> 13) + 2) << 1;
+            if (frame - offset < frame_start || frame_end - frame < count*2 + width)
+                return -1;
+            for (i = 0; i < count; i++) {
+                frame[0] = frame[1] =
+                frame[width] = frame[width + 1] = frame[-offset];
+
+                frame += 2;
+            }
+        } else if (bitbuf & (mask << 1)) {
+            frame += bytestream_get_le16(&src) * 2;
+        } else {
+            frame[0] = frame[1] =
+            frame[width] = frame[width + 1] =  *src++;
+            frame += 2;
+            frame[0] = frame[1] =
+            frame[width] = frame[width + 1] =  *src++;
+            frame += 2;
+        }
+        mask <<= 2;
+    }
+
+    return 0;
+}
+
+static int decode_bdlt(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    const uint8_t *frame_end = frame + width * height;
+    uint8_t *line_ptr;
+    int count, lines, segments;
+
+    count = bytestream_get_le16(&src);
+    if (count >= height || width * count < 0)
+        return -1;
+    frame += width * count;
+    lines = bytestream_get_le16(&src);
+    if (frame + lines * width > frame_end || src >= src_end)
+        return -1;
+
+    while (lines--) {
+        line_ptr = frame;
+        frame += width;
+        segments = *src++;
+        while (segments--) {
+            if (src_end - src < 3)
+                return -1;
+            line_ptr += *src++;
+            if (line_ptr >= frame)
+                return -1;
+            count = (int8_t)*src++;
+            if (count >= 0) {
+                if (line_ptr + count > frame || src_end - src < count)
+                    return -1;
+                bytestream_get_buffer(&src, line_ptr, count);
+            } else {
+                count = -count;
+                if (line_ptr + count > frame || src >= src_end)
+                    return -1;
+                memset(line_ptr, *src++, count);
+            }
+            line_ptr += count;
+        }
+    }
+
+    return 0;
+}
+
+static int decode_wdlt(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    const uint8_t *frame_end   = frame + width * height;
+    uint8_t *line_ptr;
+    int count, i, v, lines, segments;
+
+    lines = bytestream_get_le16(&src);
+    if (frame + lines * width > frame_end || src >= src_end)
+        return -1;
+
+    while (lines--) {
+        segments = bytestream_get_le16(&src);
+        while ((segments & 0xC000) == 0xC000) {
+            frame    -= (int16_t)segments * width;
+            if (frame >= frame_end)
+                return -1;
+            segments = bytestream_get_le16(&src);
+        }
+        if (segments & 0x8000) {
+            frame[width - 1] = segments & 0xFF;
+            segments = bytestream_get_le16(&src);
+        }
+        line_ptr = frame;
+        frame += width;
+        while (segments--) {
+            if (src_end - src < 2)
+                return -1;
+            line_ptr += *src++;
+            if (line_ptr >= frame)
+                return -1;
+            count = (int8_t)*src++;
+            if (count >= 0) {
+                if (line_ptr + count*2 > frame || src_end - src < count*2)
+                    return -1;
+                bytestream_get_buffer(&src, line_ptr, count*2);
+                line_ptr += count * 2;
+            } else {
+                count = -count;
+                if (line_ptr + count*2 > frame || src_end - src < 2)
+                    return -1;
+                v = bytestream_get_le16(&src);
+                for (i = 0; i < count; i++)
+                    bytestream_put_le16(&line_ptr, v);
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int decode_unk6(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    return -1;
+}
+
+static int decode_blck(uint8_t *frame, int width, int height,
+                       const uint8_t *src, const uint8_t *src_end)
+{
+    memset(frame, 0, width * height);
+    return 0;
+}
+
+
+typedef int (*chunk_decoder)(uint8_t *frame, int width, int height,
+                             const uint8_t *src, const uint8_t *src_end);
+
+static const chunk_decoder decoder[8] = {
+    decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
+    decode_unk6, decode_dsw1, decode_blck, decode_dds1,
+};
+
+static const char* chunk_name[8] = {
+    "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
+};
+
+static int dfa_decode_frame(AVCodecContext *avctx,
+                            void *data, int *data_size,
+                            AVPacket *avpkt)
+{
+    DfaContext *s = avctx->priv_data;
+    const uint8_t *buf = avpkt->data;
+    const uint8_t *buf_end = avpkt->data + avpkt->size;
+    const uint8_t *tmp_buf;
+    uint32_t chunk_type, chunk_size;
+    uint8_t *dst;
+    int ret;
+    int i, pal_elems;
+
+    if (s->pic.data[0])
+        avctx->release_buffer(avctx, &s->pic);
+
+    if ((ret = avctx->get_buffer(avctx, &s->pic))) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+
+    while (buf < buf_end) {
+        chunk_size = AV_RL32(buf + 4);
+        chunk_type = AV_RL32(buf + 8);
+        buf += 12;
+        if (buf_end - buf < chunk_size) {
+            av_log(avctx, AV_LOG_ERROR, "Chunk size is too big (%d bytes)\n", chunk_size);
+            return -1;
+        }
+        if (!chunk_type)
+            break;
+        if (chunk_type == 1) {
+            pal_elems = FFMIN(chunk_size / 3, 256);
+            tmp_buf = buf;
+            for (i = 0; i < pal_elems; i++) {
+                s->pal[i] = bytestream_get_be24(&tmp_buf) << 2;
+                s->pal[i] |= (s->pal[i] >> 6) & 0x333;
+            }
+            s->pic.palette_has_changed = 1;
+        } else if (chunk_type <= 9) {
+            if (decoder[chunk_type - 2](s->frame_buf, avctx->width, avctx->height,
+                                        buf, buf + chunk_size)) {
+                av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
+                       chunk_name[chunk_type - 2]);
+                return -1;
+            }
+        } else {
+            av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
+                   chunk_type);
+        }
+        buf += chunk_size;
+    }
+
+    buf = s->frame_buf;
+    dst = s->pic.data[0];
+    for (i = 0; i < avctx->height; i++) {
+        memcpy(dst, buf, avctx->width);
+        dst += s->pic.linesize[0];
+        buf += avctx->width;
+    }
+    memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
+
+    *data_size = sizeof(AVFrame);
+    *(AVFrame*)data = s->pic;
+
+    return avpkt->size;
+}
+
+static av_cold int dfa_decode_end(AVCodecContext *avctx)
+{
+    DfaContext *s = avctx->priv_data;
+
+    if (s->pic.data[0])
+        avctx->release_buffer(avctx, &s->pic);
+
+    av_freep(&s->frame_buf);
+
+    return 0;
+}
+
+AVCodec ff_dfa_decoder = {
+    "dfa",
+    AVMEDIA_TYPE_VIDEO,
+    CODEC_ID_DFA,
+    sizeof(DfaContext),
+    dfa_decode_init,
+    NULL,
+    dfa_decode_end,
+    dfa_decode_frame,
+    CODEC_CAP_DR1,
+    .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),
+};