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avcodec/sanm: implement codec37 subcodec1

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RLE-compressed stream of motion vector indices and a special opcode
to fill a block with data from the source stream.

It is used in the LucasArts "Full Throttle" blink*.san animations.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Fixes: Ticket5753
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Manuel Lauss 2025-01-09 09:03:11 +01:00 • committed by Michael Niedermayer
parent c08d300481
commit fff7737b3d
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GPG key ID: B18E8928B3948D64
1 changed files with 62 additions and 3 deletions
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65
libavcodec/sanm.c
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@ -624,8 +624,8 @@ static inline void codec37_mv(uint8_t *dst, const uint8_t *src,
static int old_codec37(SANMVideoContext *ctx, int top,
int left, int width, int height)
{
int i, j, k, l, t, run, len, code, skip, mx, my;
ptrdiff_t stride = ctx->pitch;
int i, j, k, t;
uint8_t *dst, *prev;
int skip_run = 0;
int compr = bytestream2_get_byte(&ctx->gb);
@ -665,6 +665,67 @@ static int old_codec37(SANMVideoContext *ctx, int top,
memset(ctx->frm1, 0, ctx->height * stride);
memset(ctx->frm2, 0, ctx->height * stride);
break;
case 1:
run = 0;
len = -1;
code = 0;
for (j = 0; j < height; j += 4) {
for (i = 0; i < width; i += 4) {
if (len < 0) {
if (bytestream2_get_bytes_left(&ctx->gb) < 1)
return AVERROR_INVALIDDATA;
code = bytestream2_get_byte(&ctx->gb);
len = code >> 1;
run = code & 1;
skip = 0;
} else {
skip = run;
}
if (!skip) {
if (bytestream2_get_bytes_left(&ctx->gb) < 1)
return AVERROR_INVALIDDATA;
code = bytestream2_get_byte(&ctx->gb);
if (code == 0xff) {
len--;
for (k = 0; k < 4; k++) {
for (l = 0; l < 4; l++) {
if (len < 0) {
if (bytestream2_get_bytes_left(&ctx->gb) < 1)
return AVERROR_INVALIDDATA;
code = bytestream2_get_byte(&ctx->gb);
len = code >> 1;
run = code & 1;
if (run) {
if (bytestream2_get_bytes_left(&ctx->gb) < 1)
return AVERROR_INVALIDDATA;
code = bytestream2_get_byte(&ctx->gb);
}
}
if (!run) {
if (bytestream2_get_bytes_left(&ctx->gb) < 1)
return AVERROR_INVALIDDATA;
code = bytestream2_get_byte(&ctx->gb);
}
*(dst + i + (k * stride) + l) = code;
len--;
}
}
continue;
}
}
/* 4x4 block copy from prev with MV */
mx = c37_mv[(mvoff * 255 + code) * 2];
my = c37_mv[(mvoff * 255 + code) * 2 + 1];
codec37_mv(dst + i, prev + i + mx + my * stride,
ctx->height, stride, i + mx, j + my);
len--;
}
dst += stride * 4;
prev += stride * 4;
}
break;
case 2:
if (rle_decode(ctx, dst, decoded_size))
return AVERROR_INVALIDDATA;
@ -712,8 +773,6 @@ static int old_codec37(SANMVideoContext *ctx, int top,
skip_run = bytestream2_get_byteu(&ctx->gb) + 1;
i -= 4;
} else {
int mx, my;
mx = c37_mv[(mvoff * 255 + code) * 2];
my = c37_mv[(mvoff * 255 + code) * 2 + 1];
codec37_mv(dst + i, prev + i + mx + my * stride,