* [FFmpeg-devel] [PATCH 1/2] avcodec/sanm: fix codec33/34 tile generator
2025-05-30 11:19 [FFmpeg-devel] [PATCH 0/2] avcodec/sanm: SEGA-CD codecs support Manuel Lauss
@ 2025-05-30 11:19 ` Manuel Lauss
2025-05-30 11:19 ` [FFmpeg-devel] [PATCH 2/2] avcodec/sanm: codec31/32 (SEGA-CD) support Manuel Lauss
1 sibling, 0 replies; 3+ messages in thread
From: Manuel Lauss @ 2025-05-30 11:19 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Manuel Lauss
tested with LVL11/L11PLAY.ANM from Rebel Assault Sega-CD release.
---
libavcodec/sanm.c | 33 +++++++++++++++------------------
1 file changed, 15 insertions(+), 18 deletions(-)
diff --git a/libavcodec/sanm.c b/libavcodec/sanm.c
index 00bfef00fe..46cad3c703 100644
--- a/libavcodec/sanm.c
+++ b/libavcodec/sanm.c
@@ -493,14 +493,12 @@ static void codec33_gen_tiles(SANMVideoContext *ctx, int8_t param1)
for (k = 0; k < 8; k++) {
j = i + param1;
l = k + param1;
- p = (j + k) / 2;
- j = (j + p) / 2;
- m = l / 2;
- n = (i + param1);
- o = (k + param1);
-
- *dst++ = p; *dst++ = p; *dst++ = j; *dst++ = n;
- *dst++ = p; *dst++ = p; *dst++ = j; *dst++ = i;
+ p = (j + l) >> 1;
+ n = (j + p) >> 1;
+ m = (p + l) >> 1;
+
+ *dst++ = p; *dst++ = p; *dst++ = n; *dst++ = j;
+ *dst++ = p; *dst++ = p; *dst++ = n; *dst++ = j;
*dst++ = m; *dst++ = m; *dst++ = p; *dst++ = j;
*dst++ = l; *dst++ = l; *dst++ = m; *dst++ = p;
}
@@ -510,8 +508,8 @@ static void codec33_gen_tiles(SANMVideoContext *ctx, int8_t param1)
for (k = 0; k < 8; k++) {
j = i + param1;
l = k + param1;
- n = ((j + l) / 2);
- m = ((l + n) / 2);
+ n = (j + l) >> 1;
+ m = (l + n) >> 1;
*dst++ = j; *dst++ = j; *dst++ = j; *dst++ = j;
*dst++ = n; *dst++ = n; *dst++ = n; *dst++ = n;
@@ -524,13 +522,12 @@ static void codec33_gen_tiles(SANMVideoContext *ctx, int8_t param1)
for (k = 0; k < 8; k++) {
j = i + param1;
l = k + param1;
- m = (j + l) / 2;
- n = (j + m) / 2;
- o = m / 2;
- p = j & 0xff;
+ m = (j + l) >> 1;
+ n = (j + m) >> 1;
+ o = (l + m) >> 1;
- *dst++ = p; *dst++ = p; *dst++ = n; *dst++ = m;
- *dst++ = p; *dst++ = p; *dst++ = n; *dst++ = m;
+ *dst++ = j; *dst++ = j; *dst++ = n; *dst++ = m;
+ *dst++ = j; *dst++ = j; *dst++ = n; *dst++ = m;
*dst++ = n; *dst++ = n; *dst++ = m; *dst++ = o;
*dst++ = m; *dst++ = m; *dst++ = o; *dst++ = l;
}
@@ -540,8 +537,8 @@ static void codec33_gen_tiles(SANMVideoContext *ctx, int8_t param1)
for (k = 0; k < 8; k++) {
j = i + param1;
l = k + param1;
- m = (j + l) / 2;
- n = m / 2;
+ m = (j + l) >> 1;
+ n = (l + m) >> 1;
*dst++ = j; *dst++ = m; *dst++ = n; *dst++ = l;
*dst++ = j; *dst++ = m; *dst++ = n; *dst++ = l;
--
2.49.0
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^ permalink raw reply [flat|nested] 3+ messages in thread* [FFmpeg-devel] [PATCH 2/2] avcodec/sanm: codec31/32 (SEGA-CD) support
2025-05-30 11:19 [FFmpeg-devel] [PATCH 0/2] avcodec/sanm: SEGA-CD codecs support Manuel Lauss
2025-05-30 11:19 ` [FFmpeg-devel] [PATCH 1/2] avcodec/sanm: fix codec33/34 tile generator Manuel Lauss
@ 2025-05-30 11:19 ` Manuel Lauss
1 sibling, 0 replies; 3+ messages in thread
From: Manuel Lauss @ 2025-05-30 11:19 UTC (permalink / raw)
To: ffmpeg-devel; +Cc: Manuel Lauss
codec31/32 are like codec1/3 (RLE coding) but with 2 4-bit pixels per byte.
---
libavcodec/sanm.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/libavcodec/sanm.c b/libavcodec/sanm.c
index 46cad3c703..975f33992f 100644
--- a/libavcodec/sanm.c
+++ b/libavcodec/sanm.c
@@ -928,6 +928,62 @@ static int old_codec1(SANMVideoContext *ctx, GetByteContext *gb, int top,
return 0;
}
+static int old_codec31(SANMVideoContext *ctx, GetByteContext *gb, int top,
+ int left, int width, int height, int p1, int opaque)
+{
+ int i, j, len, flag, code, val, end, pxoff;
+ const int maxpxo = ctx->height * ctx->pitch;
+ uint8_t *dst = (uint8_t *)ctx->fbuf;
+
+ for (i = 0; i < height; i++) {
+ if (bytestream2_get_bytes_left(gb) < 2)
+ return AVERROR_INVALIDDATA;
+
+ len = bytestream2_get_le16u(gb);
+ end = bytestream2_tell(gb) + len;
+
+ pxoff = left + ((top + i) * ctx->pitch);
+ while (bytestream2_tell(gb) < end) {
+ if (bytestream2_get_bytes_left(gb) < 2)
+ return AVERROR_INVALIDDATA;
+
+ code = bytestream2_get_byteu(gb);
+ flag = code & 1;
+ code = (code >> 1) + 1;
+ if (flag) {
+ val = bytestream2_get_byteu(gb);
+ for (j = 0; j < code; j++) {
+ if ((0 != (val & 0xf)) || opaque) {
+ if (pxoff >= 0 && pxoff < maxpxo)
+ *(dst + pxoff) = p1 + (val & 0xf);
+ }
+ pxoff++;
+ if ((0 != (val >> 4)) || opaque) {
+ if (pxoff >= 0 && pxoff < maxpxo)
+ *(dst + pxoff) = p1 + (val >> 4);
+ }
+ pxoff++;
+ }
+ } else {
+ if (bytestream2_get_bytes_left(gb) < code)
+ return AVERROR_INVALIDDATA;
+ for (j = 0; j < code; j++) {
+ val = bytestream2_get_byteu(gb);
+ if ((pxoff >= 0) && (pxoff < maxpxo) && ((0 != (val & 0xf)) || opaque))
+ *(dst + pxoff) = p1 + (val & 0xf);
+ pxoff++;
+ if ((pxoff >= 0) && (pxoff < maxpxo) && ((0 != (val >> 4)) || opaque))
+ *(dst + pxoff) = p1 + (val >> 4);
+ pxoff++;
+ }
+ }
+ }
+ }
+ ctx->rotate_code = 0;
+
+ return 0;
+}
+
static int old_codec2(SANMVideoContext *ctx, GetByteContext *gb, int top,
int left, int width, int height)
{
@@ -1708,6 +1764,9 @@ static int process_frame_obj(SANMVideoContext *ctx, GetByteContext *gb)
return old_codec21(ctx, gb, top, left, w, h);
case 23:
return old_codec23(ctx, gb, top, left, w, h, param, parm2);
+ case 31:
+ case 32:
+ return old_codec31(ctx, gb, top, left, w, h, param, (codec == 32));
case 37:
ret = old_codec37(ctx, w, h); break;
case 45:
--
2.49.0
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^ permalink raw reply [flat|nested] 3+ messages in thread