[FFmpeg-devel] [PATCH 0/2] Origin Wing Commander IV video decoder
Kostya
kostya.shishkov
Fri Feb 4 23:47:26 CET 2011
On Fri, Feb 04, 2011 at 04:42:15PM -0500, Ronald S. Bultje wrote:
> Hi,
>
> On Thu, Feb 3, 2011 at 4:32 AM, Kostya <kostya.shishkov at gmail.com> wrote:
> > + const int pic_size = avctx->width * avctx->height;
>
> You calculate that in various places, and it never changes. Just store
> it in the context.
done
> > +static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
> [..]
> + chroma_off = AV_RL32(buf + 4);
> + if (!chroma_off)
> + return 0;
> + if (chroma_off >= avpkt->size) {
>
> if (chroma_off + 10 >= avpkt->size) {, because below you read various
> more, if you want to be exact.
done
> > + src = avpkt->data + 4 + chroma_off;
> > + table = src + 2;
> > + mode = bytestream_get_le16(&src);
> > + offset = bytestream_get_le16(&src) * 2;
>
> > + dec_size = xan_unpack(s->scratch_buffer, pic_size, src + offset,
> > + avpkt->size - offset - (src - avpkt->data));
>
> src+offset can overread but is never checked in xan_unpack() before
> reading opcode.
added a check
> > + if (mode > 1)
> > + av_log(avctx, AV_LOG_WARNING, "Unknown chroma coding mode %d\n", mode);
>
> But no error? Most likely damaged file, right?
original decoder did not care so I'm dropping this check
> > + if (mode) {
> > + for (j = 0; j < avctx->height / 2; j++) {
> > + for (i = 0; i < avctx->width / 2; i++) {
>
> (unimportant) / 2 -> >> 1.
changed
> > + for (j = 0; j < avctx->height / 4; j++) {
> > + for (i = 0; i < avctx->width / 2; i += 2) {
>
> Same.
this too
> > +static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)
> [..]
> > + ybuf = s->y_buffer;
> > + last = *src++;
> > + ybuf[0] = last << 1;
> > + for (j = 1; j < avctx->width - 1; j += 2) {
> > + cur = (last + *src++) & 0x1F;
> > + ybuf[j] = last + cur;
> > + ybuf[j+1] = cur << 1;
> > + last = cur;
> > + }
> > + ybuf[j] = last << 1;
> > + prev_buf = ybuf;
> > + ybuf += avctx->width;
> > +
> > + for (i = 1; i < avctx->height; i++) {
> > + last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
> > + ybuf[0] = last << 1;
> > + for (j = 1; j < avctx->width - 1; j += 2) {
> > + cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
> > + ybuf[j] = last + cur;
> > + ybuf[j+1] = cur << 1;
> > + last = cur;
> > + }
> > + ybuf[j] = last << 1;
> > + prev_buf = ybuf;
> > + ybuf += avctx->width;
> [..]
> > + src = s->y_buffer;
> > + ybuf = s->pic.data[0];
> > + for (j = 0; j < avctx->height; j++) {
> > + for (i = 0; i < avctx->width; i++)
> > + ybuf[i] = (src[i] << 2) | (src[i] >> 3);
> > + src += avctx->width;
> > + ybuf += s->pic.linesize[0];
> > + }
> [..]
> > +static int xan_decode_frame_type1(AVCodecContext *avctx, AVPacket *avpkt)
> [..]
> > + ybuf = s->y_buffer;
> > + for (i = 0; i < avctx->height; i++) {
> > + last = (ybuf[0] + (*src++ << 1)) & 0x3F;
> > + ybuf[0] = last;
> > + for (j = 1; j < avctx->width - 1; j += 2) {
> > + cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
> > + ybuf[j] = (last + cur) >> 1;
> > + ybuf[j+1] = cur;
> > + last = cur;
> > + }
> > + ybuf[j] = last;
> > + ybuf += avctx->width;
> > + }
> > +
> > + src = s->y_buffer;
> > + ybuf = s->pic.data[0];
> > + for (j = 0; j < avctx->height; j++) {
> > + for (i = 0; i < avctx->width; i++)
> > + ybuf[i] = (src[i] << 2) | (src[i] >> 3);
> > + src += avctx->width;
> > + ybuf += s->pic.linesize[0];
> > + }
>
> Can src ever overread here?
Nope, it's always width*height/2 and unpack function checks if exact number
of bytes were read.
> Ronald
>From none Fri Feb 4 23:41:07 2011
From: none (Kostya)
Date: Fri, 4 Feb 2011 23:41:07 +0100
Subject: [PATCH] Xan4 decoder
Message-ID: <mailman.574.1296859626.1307.ffmpeg-devel at mplayerhq.hu>
---
Changelog | 1 +
doc/general.texi | 2 +
libavcodec/Makefile | 2 +-
libavcodec/allcodecs.c | 1 +
libavcodec/avcodec.h | 2 +-
libavcodec/xxan.c | 429 ++++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 435 insertions(+), 2 deletions(-)
create mode 100644 libavcodec/xxan.c
diff --git a/Changelog b/Changelog
index 8b7efb6..a85a9d3 100644
--- a/Changelog
+++ b/Changelog
@@ -74,6 +74,7 @@ version <next>:
- Lagarith decoder
- ffmpeg -copytb option added
- IVF muxer added
+- Wing Commander IV movies decoder added
version 0.6:
diff --git a/doc/general.texi b/doc/general.texi
index 950159f..ad34c70 100644
--- a/doc/general.texi
+++ b/doc/general.texi
@@ -511,6 +511,8 @@ following image formats are supported:
@tab not completely working
@item Wing Commander III / Xan @tab @tab X
@tab Used in Wing Commander III .MVE files.
+ at item Wing Commander IV / Xan @tab @tab X
+ @tab Used in Wing Commander IV.
@item Winnov WNV1 @tab @tab X
@item WMV7 @tab X @tab X
@item YAMAHA SMAF @tab X @tab X
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 6a0a05b..fa6c0bb 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -415,7 +415,7 @@ OBJS-$(CONFIG_WNV1_DECODER) += wnv1.o
OBJS-$(CONFIG_WS_SND1_DECODER) += ws-snd1.o
OBJS-$(CONFIG_XAN_DPCM_DECODER) += dpcm.o
OBJS-$(CONFIG_XAN_WC3_DECODER) += xan.o
-OBJS-$(CONFIG_XAN_WC4_DECODER) += xan.o
+OBJS-$(CONFIG_XAN_WC4_DECODER) += xxan.o
OBJS-$(CONFIG_XL_DECODER) += xl.o
OBJS-$(CONFIG_XSUB_DECODER) += xsubdec.o
OBJS-$(CONFIG_XSUB_ENCODER) += xsubenc.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 04c5c6a..108a3ab 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -214,6 +214,7 @@ void avcodec_register_all(void)
REGISTER_DECODER (WMV3_VDPAU, wmv3_vdpau);
REGISTER_DECODER (WNV1, wnv1);
REGISTER_DECODER (XAN_WC3, xan_wc3);
+ REGISTER_DECODER (XAN_WC4, xan_wc4);
REGISTER_DECODER (XL, xl);
REGISTER_DECODER (YOP, yop);
REGISTER_ENCDEC (ZLIB, zlib);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index dbfb777..280ad35 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -32,7 +32,7 @@
#include "libavutil/cpu.h"
#define LIBAVCODEC_VERSION_MAJOR 52
-#define LIBAVCODEC_VERSION_MINOR 109
+#define LIBAVCODEC_VERSION_MINOR 110
#define LIBAVCODEC_VERSION_MICRO 0
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
diff --git a/libavcodec/xxan.c b/libavcodec/xxan.c
new file mode 100644
index 0000000..4f5d1a9
--- /dev/null
+++ b/libavcodec/xxan.c
@@ -0,0 +1,429 @@
+/*
+ * Wing Commander/Xan Video Decoder
+ * Copyright (C) 2011 Konstantin Shishkov
+ * based on work by Mike Melanson
+ *
+ * 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 "avcodec.h"
+#include "libavutil/intreadwrite.h"
+#include "bytestream.h"
+#define ALT_BITSTREAM_READER_LE
+#include "get_bits.h"
+// for av_memcpy_backptr
+#include "libavutil/lzo.h"
+
+typedef struct XanContext {
+ AVCodecContext *avctx;
+ AVFrame pic;
+
+ uint8_t *y_buffer;
+ uint8_t *scratch_buffer;
+ int buffer_size;
+} XanContext;
+
+static av_cold int xan_decode_init(AVCodecContext *avctx)
+{
+ XanContext *s = avctx->priv_data;
+
+ s->avctx = avctx;
+
+ avctx->pix_fmt = PIX_FMT_YUV420P;
+
+ s->buffer_size = avctx->width * avctx->height;
+ s->y_buffer = av_malloc(s->buffer_size);
+ if (!s->y_buffer)
+ return AVERROR(ENOMEM);
+ s->scratch_buffer = av_malloc(s->buffer_size + 130);
+ if (!s->scratch_buffer) {
+ av_freep(&s->y_buffer);
+ return AVERROR(ENOMEM);
+ }
+
+ return 0;
+}
+
+static int xan_unpack_luma(const uint8_t *src, const int src_size,
+ uint8_t *dst, const int dst_size)
+{
+ int tree_size, eof;
+ const uint8_t *tree;
+ int bits, mask;
+ int tree_root, node;
+ const uint8_t *dst_end = dst + dst_size;
+ const uint8_t *src_end = src + src_size;
+
+ tree_size = *src++;
+ eof = *src++;
+ tree = src - eof * 2 - 2;
+ tree_root = eof + tree_size;
+ src += tree_size * 2;
+
+ node = tree_root;
+ bits = *src++;
+ mask = 0x80;
+ for (;;) {
+ int bit = !!(bits & mask);
+ mask >>= 1;
+ node = tree[node*2 + bit];
+ if (node == eof)
+ break;
+ if (node < eof) {
+ *dst++ = node;
+ if (dst > dst_end)
+ break;
+ node = tree_root;
+ }
+ if (!mask) {
+ bits = *src++;
+ if (src > src_end)
+ break;
+ mask = 0x80;
+ }
+ }
+ return dst != dst_end;
+}
+
+/* almost the same as in xan_wc3 decoder */
+static int xan_unpack(uint8_t *dest, const int dest_len,
+ const uint8_t *src, const int src_len)
+{
+ uint8_t opcode;
+ int size;
+ uint8_t *orig_dest = dest;
+ const uint8_t *src_end = src + src_len;
+ const uint8_t *dest_end = dest + dest_len;
+
+ while (dest < dest_end) {
+ opcode = *src++;
+
+ if (opcode < 0xe0) {
+ int size2, back;
+ if ((opcode & 0x80) == 0) {
+ size = opcode & 3;
+ back = ((opcode & 0x60) << 3) + *src++ + 1;
+ size2 = ((opcode & 0x1c) >> 2) + 3;
+ } else if ((opcode & 0x40) == 0) {
+ size = *src >> 6;
+ back = (bytestream_get_be16(&src) & 0x3fff) + 1;
+ size2 = (opcode & 0x3f) + 4;
+ } else {
+ size = opcode & 3;
+ back = ((opcode & 0x10) << 12) + bytestream_get_be16(&src) + 1;
+ size2 = ((opcode & 0x0c) << 6) + *src++ + 5;
+ if (size + size2 > dest_end - dest)
+ break;
+ }
+ if (src + size > src_end || dest + size + size2 > dest_end)
+ return -1;
+ bytestream_get_buffer(&src, dest, size);
+ dest += size;
+ av_memcpy_backptr(dest, back, size2);
+ dest += size2;
+ } else {
+ int finish = opcode >= 0xfc;
+
+ size = finish ? opcode & 3 : ((opcode & 0x1f) << 2) + 4;
+ if (src + size > src_end || dest + size > dest_end)
+ return -1;
+ bytestream_get_buffer(&src, dest, size);
+ dest += size;
+ if (finish)
+ break;
+ }
+ }
+ return dest - orig_dest;
+}
+
+static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ const uint8_t *buf = avpkt->data;
+ XanContext *s = avctx->priv_data;
+ uint8_t *U, *V;
+ unsigned chroma_off;
+ int val, uval, vval;
+ int i, j;
+ const uint8_t *src, *src_end;
+ const uint8_t *table;
+ int mode, offset, dec_size;
+
+ chroma_off = AV_RL32(buf + 4);
+ if (!chroma_off)
+ return 0;
+ if (chroma_off + 10 >= avpkt->size) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid chroma block position\n");
+ return -1;
+ }
+ src = avpkt->data + 4 + chroma_off;
+ table = src + 2;
+ mode = bytestream_get_le16(&src);
+ offset = bytestream_get_le16(&src) * 2;
+
+ if (src + offset >= avpkt->data + avpkt->size) {
+ av_log(avctx, AV_LOG_ERROR, "Invalid chroma block offset\n");
+ return -1;
+ }
+
+ memset(s->scratch_buffer, 0, s->buffer_size);
+ dec_size = xan_unpack(s->scratch_buffer, s->buffer_size, src + offset,
+ avpkt->size - offset - (src - avpkt->data));
+ if (dec_size < 0) {
+ av_log(avctx, AV_LOG_ERROR, "Chroma unpacking failed\n");
+ return -1;
+ }
+
+ U = s->pic.data[1];
+ V = s->pic.data[2];
+ src = s->scratch_buffer;
+ src_end = src + dec_size;
+ if (mode) {
+ for (j = 0; j < avctx->height >> 1; j++) {
+ for (i = 0; i < avctx->width >> 1; i++) {
+ val = *src++;
+ if (val) {
+ val = AV_RL16(table + (val << 1));
+ uval = (val >> 3) & 0xF8;
+ vval = (val >> 8) & 0xF8;
+ U[i] = uval | (uval >> 5);
+ V[i] = vval | (vval >> 5);
+ }
+ if (src == src_end)
+ return 0;
+ }
+ U += s->pic.linesize[1];
+ V += s->pic.linesize[2];
+ }
+ } else {
+ uint8_t *U2 = U + s->pic.linesize[1];
+ uint8_t *V2 = V + s->pic.linesize[2];
+
+ for (j = 0; j < avctx->height >> 2; j++) {
+ for (i = 0; i < avctx->width >> 1; i += 2) {
+ val = *src++;
+ if (val) {
+ val = AV_RL16(table + (val << 1));
+ uval = (val >> 3) & 0xF8;
+ vval = (val >> 8) & 0xF8;
+ U[i] = U[i+1] = U2[i] = U2[i+1] = uval | (uval >> 5);
+ V[i] = V[i+1] = V2[i] = V2[i+1] = vval | (vval >> 5);
+ }
+ }
+ U += s->pic.linesize[1] * 2;
+ V += s->pic.linesize[2] * 2;
+ U2 += s->pic.linesize[1] * 2;
+ V2 += s->pic.linesize[2] * 2;
+ }
+ }
+
+ return 0;
+}
+
+static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ const uint8_t *buf = avpkt->data;
+ XanContext *s = avctx->priv_data;
+ uint8_t *ybuf, *prev_buf, *src = s->scratch_buffer;
+ unsigned chroma_off, corr_off;
+ int cur, last, size;
+ int i, j;
+ int ret;
+
+ corr_off = AV_RL32(buf + 8);
+ chroma_off = AV_RL32(buf + 4);
+
+ if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
+ return ret;
+
+ size = avpkt->size - 4;
+ if (corr_off >= avpkt->size) {
+ av_log(avctx, AV_LOG_WARNING, "Ignoring invalid correction block position\n");
+ corr_off = 0;
+ }
+ if (corr_off)
+ size = corr_off;
+ if (chroma_off)
+ size = FFMIN(size, chroma_off);
+ ret = xan_unpack_luma(buf + 12, size, src, s->buffer_size >> 1);
+ if (ret) {
+ av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
+ return ret;
+ }
+
+ ybuf = s->y_buffer;
+ last = *src++;
+ ybuf[0] = last << 1;
+ for (j = 1; j < avctx->width - 1; j += 2) {
+ cur = (last + *src++) & 0x1F;
+ ybuf[j] = last + cur;
+ ybuf[j+1] = cur << 1;
+ last = cur;
+ }
+ ybuf[j] = last << 1;
+ prev_buf = ybuf;
+ ybuf += avctx->width;
+
+ for (i = 1; i < avctx->height; i++) {
+ last = ((prev_buf[0] >> 1) + *src++) & 0x1F;
+ ybuf[0] = last << 1;
+ for (j = 1; j < avctx->width - 1; j += 2) {
+ cur = ((prev_buf[j + 1] >> 1) + *src++) & 0x1F;
+ ybuf[j] = last + cur;
+ ybuf[j+1] = cur << 1;
+ last = cur;
+ }
+ ybuf[j] = last << 1;
+ prev_buf = ybuf;
+ ybuf += avctx->width;
+ }
+
+ if (corr_off) {
+ int corr_end, dec_size;
+
+ corr_end = avpkt->size;
+ if (chroma_off > corr_off)
+ corr_end = chroma_off;
+ dec_size = xan_unpack(s->scratch_buffer, s->buffer_size,
+ avpkt->data + 8 + corr_off,
+ corr_end - corr_off);
+ if (dec_size < 0)
+ dec_size = 0;
+ for (i = 0; i < dec_size; i++)
+ s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
+ }
+
+ src = s->y_buffer;
+ ybuf = s->pic.data[0];
+ for (j = 0; j < avctx->height; j++) {
+ for (i = 0; i < avctx->width; i++)
+ ybuf[i] = (src[i] << 2) | (src[i] >> 3);
+ src += avctx->width;
+ ybuf += s->pic.linesize[0];
+ }
+
+ return 0;
+}
+
+static int xan_decode_frame_type1(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ const uint8_t *buf = avpkt->data;
+ XanContext *s = avctx->priv_data;
+ uint8_t *ybuf, *src = s->scratch_buffer;
+ int cur, last;
+ int i, j;
+ int ret;
+
+ if ((ret = xan_decode_chroma(avctx, avpkt)) != 0)
+ return ret;
+
+ ret = xan_unpack_luma(buf + 16, avpkt->size - 16, src,
+ s->buffer_size >> 1);
+ if (ret) {
+ av_log(avctx, AV_LOG_ERROR, "Luma decoding failed\n");
+ return ret;
+ }
+
+ ybuf = s->y_buffer;
+ for (i = 0; i < avctx->height; i++) {
+ last = (ybuf[0] + (*src++ << 1)) & 0x3F;
+ ybuf[0] = last;
+ for (j = 1; j < avctx->width - 1; j += 2) {
+ cur = (ybuf[j + 1] + (*src++ << 1)) & 0x3F;
+ ybuf[j] = (last + cur) >> 1;
+ ybuf[j+1] = cur;
+ last = cur;
+ }
+ ybuf[j] = last;
+ ybuf += avctx->width;
+ }
+
+ src = s->y_buffer;
+ ybuf = s->pic.data[0];
+ for (j = 0; j < avctx->height; j++) {
+ for (i = 0; i < avctx->width; i++)
+ ybuf[i] = (src[i] << 2) | (src[i] >> 3);
+ src += avctx->width;
+ ybuf += s->pic.linesize[0];
+ }
+
+ return 0;
+}
+
+static int xan_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ AVPacket *avpkt)
+{
+ XanContext *s = avctx->priv_data;
+ int ftype;
+ int ret;
+
+ s->pic.reference = 1;
+ s->pic.buffer_hints = FF_BUFFER_HINTS_VALID |
+ FF_BUFFER_HINTS_PRESERVE |
+ FF_BUFFER_HINTS_REUSABLE;
+ if ((ret = avctx->reget_buffer(avctx, &s->pic))) {
+ av_log(s->avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
+ return ret;
+ }
+
+ ftype = AV_RL32(avpkt->data);
+ switch (ftype) {
+ case 0:
+ ret = xan_decode_frame_type0(avctx, avpkt);
+ break;
+ case 1:
+ ret = xan_decode_frame_type1(avctx, avpkt);
+ break;
+ default:
+ av_log(avctx, AV_LOG_ERROR, "Unknown frame type %d\n", ftype);
+ return -1;
+ }
+ if (ret)
+ return ret;
+
+ *data_size = sizeof(AVFrame);
+ *(AVFrame*)data = s->pic;
+
+ return avpkt->size;
+}
+
+static av_cold int xan_decode_end(AVCodecContext *avctx)
+{
+ XanContext *s = avctx->priv_data;
+
+ if (s->pic.data[0])
+ avctx->release_buffer(avctx, &s->pic);
+
+ av_freep(&s->y_buffer);
+ av_freep(&s->scratch_buffer);
+
+ return 0;
+}
+
+AVCodec ff_xan_wc4_decoder = {
+ "xan_wc4",
+ AVMEDIA_TYPE_VIDEO,
+ CODEC_ID_XAN_WC4,
+ sizeof(XanContext),
+ xan_decode_init,
+ NULL,
+ xan_decode_end,
+ xan_decode_frame,
+ CODEC_CAP_DR1,
+ .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
+};
+
--
1.7.0.4
--d6Gm4EdcadzBjdND--
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