[FFmpeg-cvslog] avcodec/sanm: SMUSH codec48 decoder
Manuel Lauss
git at videolan.org
Fri Jan 3 01:12:31 EET 2025
ffmpeg | branch: master | Manuel Lauss <manuel.lauss at gmail.com> | Mon Dec 16 17:08:01 2024 +0100| [b22ce90d4228d1cb7727775cc848613ac31b97e9] | committer: Marton Balint
avcodec/sanm: SMUSH codec48 decoder
Adds a decoder for the SMUSH codec48 video encoding, as is used by
the LucasArts game "Mysteries of the Sith".
Signed-off-by: Manuel Lauss <manuel.lauss at gmail.com>
Signed-off-by: Marton Balint <cus at passwd.hu>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b22ce90d4228d1cb7727775cc848613ac31b97e9
---
libavcodec/sanm.c | 223 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 223 insertions(+)
diff --git a/libavcodec/sanm.c b/libavcodec/sanm.c
index 8bcffb1e90..a278ef24b1 100644
--- a/libavcodec/sanm.c
+++ b/libavcodec/sanm.c
@@ -995,6 +995,227 @@ static int old_codec47(SANMVideoContext *ctx, int top,
return 0;
}
+// scale 4x4 input block to an 8x8 output block
+static void c48_4to8(uint8_t *dst, const uint8_t *src, const uint16_t w)
+{
+ uint16_t p;
+ // dst is always at least 16bit aligned
+ for (int i = 0; i < 4; i++) {
+ for (int j = 0; j < 8; j += 2) {
+ p = *src++;
+ p = (p << 8) | p;
+ *((uint16_t *)(dst + w * 0 + j)) = p;
+ *((uint16_t *)(dst + w * 1 + j)) = p;
+ }
+ dst += w * 2;
+ }
+}
+
+static int codec48_block(SANMVideoContext *ctx, uint8_t *dst, uint8_t *db,
+ const uint16_t w)
+{
+ uint8_t opc, sb[16];
+ int i, j, k, l;
+ int16_t mvofs;
+ uint32_t ofs;
+
+ if (bytestream2_get_bytes_left(&ctx->gb) < 1)
+ return 1;
+
+ opc = bytestream2_get_byteu(&ctx->gb);
+ switch (opc) {
+ case 0xFF: // 1x1 -> 8x8 block scale
+ if (bytestream2_get_bytes_left(&ctx->gb) < 1)
+ return 1;
+
+ opc = bytestream2_get_byteu(&ctx->gb);
+ for (i = 0; i < 16; i++)
+ sb[i] = opc;
+ c48_4to8(dst, sb, w);
+ break;
+ case 0xFE: // 1x 8x8 copy from deltabuf, 16bit mv from source
+ if (bytestream2_get_bytes_left(&ctx->gb) < 2)
+ return 1;
+ mvofs = bytestream2_get_le16(&ctx->gb);
+ for (i = 0; i < 8; i++) {
+ ofs = w * i;
+ for (k = 0; k < 8; k++)
+ *(dst + ofs + k) = *(db + ofs + k + mvofs);
+ }
+ break;
+ case 0xFD: // 2x2 -> 8x8 block scale
+ if (bytestream2_get_bytes_left(&ctx->gb) < 4)
+ return 1;
+ sb[ 5] = bytestream2_get_byteu(&ctx->gb);
+ sb[ 7] = bytestream2_get_byteu(&ctx->gb);
+ sb[13] = bytestream2_get_byteu(&ctx->gb);
+ sb[15] = bytestream2_get_byteu(&ctx->gb);
+
+ sb[0] = sb[1] = sb[4] = sb[5];
+ sb[2] = sb[3] = sb[6] = sb[7];
+ sb[8] = sb[9] = sb[12] = sb[13];
+ sb[10] = sb[11] = sb[14] = sb[15];
+ c48_4to8(dst, sb, w);
+ break;
+ case 0xFC: // 4x copy 4x4 block, per-block c37_mv from source
+ if (bytestream2_get_bytes_left(&ctx->gb) < 4)
+ return 1;
+ for (i = 0; i < 8; i += 4) {
+ for (k = 0; k < 8; k += 4) {
+ opc = bytestream2_get_byteu(&ctx->gb);
+ mvofs = c37_mv[opc * 2] + (c37_mv[opc * 2 + 1] * w);
+ for (j = 0; j < 4; j++) {
+ ofs = (w * (j + i)) + k;
+ for (l = 0; l < 4; l++)
+ *(dst + ofs + l) = *(db + ofs + l + mvofs);
+ }
+ }
+ }
+ break;
+ case 0xFB: // Copy 4x 4x4 blocks, per-block mv from source
+ if (bytestream2_get_bytes_left(&ctx->gb) < 8)
+ return 1;
+ for (i = 0; i < 8; i += 4) {
+ for (k = 0; k < 8; k += 4) {
+ mvofs = bytestream2_get_le16(&ctx->gb);
+ for (j = 0; j < 4; j++) {
+ ofs = (w * (j + i)) + k;
+ for (l = 0; l < 4; l++)
+ *(dst + ofs + l) = *(db + ofs + l + mvofs);
+ }
+ }
+ }
+ break;
+ case 0xFA: // scale 4x4 input block to 8x8 dest block
+ if (bytestream2_get_bytes_left(&ctx->gb) < 16)
+ return 1;
+ bytestream2_get_bufferu(&ctx->gb, sb, 16);
+ c48_4to8(dst, sb, w);
+ break;
+ case 0xF9: // 16x 2x2 copy from delta, per-block c37_mv from source
+ if (bytestream2_get_bytes_left(&ctx->gb) < 16)
+ return 1;
+ for (i = 0; i < 8; i += 2) {
+ for (j = 0; j < 8; j += 2) {
+ ofs = (w * i) + j;
+ opc = bytestream2_get_byteu(&ctx->gb);
+ mvofs = c37_mv[opc * 2] + (c37_mv[opc * 2 + 1] * w);
+ for (l = 0; l < 2; l++) {
+ *(dst + ofs + l + 0) = *(db + ofs + l + 0 + mvofs);
+ *(dst + ofs + l + w) = *(db + ofs + l + w + mvofs);
+ }
+ }
+ }
+ break;
+ case 0xF8: // 16x 2x2 blocks copy, 16bit mv from source
+ if (bytestream2_get_bytes_left(&ctx->gb) < 32)
+ return 1;
+ for (i = 0; i < 8; i += 2) {
+ for (j = 0; j < 8; j += 2) {
+ ofs = w * i + j;
+ mvofs = bytestream2_get_le16(&ctx->gb);
+ for (l = 0; l < 2; l++) {
+ *(dst + ofs + l + 0) = *(db + ofs + l + 0 + mvofs);
+ *(dst + ofs + l + w) = *(db + ofs + l + w + mvofs);
+ }
+ }
+ }
+ break;
+ case 0xF7: // copy 8x8 block from src to dest
+ if (bytestream2_get_bytes_left(&ctx->gb) < 64)
+ return 1;
+ for (i = 0; i < 8; i++) {
+ ofs = i * w;
+ for (l = 0; l < 8; l++)
+ *(dst + ofs + l) = bytestream2_get_byteu(&ctx->gb);
+ }
+ break;
+ default: // copy 8x8 block from prev, c37_mv from source
+ mvofs = c37_mv[opc * 2] + (c37_mv[opc * 2 + 1] * w);
+ for (i = 0; i < 8; i++) {
+ ofs = i * w;
+ for (l = 0; l < 8; l++)
+ *(dst + ofs + l) = *(db + ofs + l + mvofs);
+ }
+ break;
+ }
+ return 0;
+}
+
+static int old_codec48(SANMVideoContext *ctx, int width, int height)
+{
+ uint8_t *dst, *prev;
+ int compr = bytestream2_get_byte(&ctx->gb);
+ int mvidx = bytestream2_get_byte(&ctx->gb);
+ int seq = bytestream2_get_le16(&ctx->gb);
+ uint32_t decoded_size = bytestream2_get_le32(&ctx->gb);
+ int i, j, flags;
+
+ // all codec48 videos use 1, but just to be safe...
+ if (mvidx != 1) {
+ av_log(ctx->avctx, AV_LOG_ERROR, "Invalid motion base value %d.\n", mvidx);
+ return AVERROR_INVALIDDATA;
+ }
+
+ bytestream2_skip(&ctx->gb, 4);
+ flags = bytestream2_get_byte(&ctx->gb);
+ bytestream2_skip(&ctx->gb, 3);
+
+ if (flags & 8) {
+ if (bytestream2_get_bytes_left(&ctx->gb) < 0x8080)
+ return AVERROR_INVALIDDATA;
+ codec47_read_interptable(ctx);
+ }
+
+ dst = (uint8_t*)ctx->frm0;
+ prev = (uint8_t*)ctx->frm2;
+
+ if (!seq) {
+ ctx->prev_seq = -1;
+ memset(prev, 0, ctx->aligned_height * width);
+ }
+
+ switch (compr) {
+ case 0:
+ if (bytestream2_get_bytes_left(&ctx->gb) < width * height)
+ return AVERROR_INVALIDDATA;
+ for (j = 0; j < height; j++) {
+ bytestream2_get_bufferu(&ctx->gb, dst, width);
+ dst += width;
+ }
+ break;
+ case 2:
+ if (rle_decode(ctx, dst, decoded_size))
+ return AVERROR_INVALIDDATA;
+ break;
+ case 3:
+ if (seq == ctx->prev_seq + 1) {
+ for (j = 0; j < height; j += 8) {
+ for (i = 0; i < width; i += 8) {
+ if (codec48_block(ctx, dst + i, prev + i, width))
+ return AVERROR_INVALIDDATA;
+ }
+ dst += width * 8;
+ prev += width * 8;
+ }
+ }
+ break;
+ case 5:
+ if (bytestream2_get_bytes_left(&ctx->gb) < ((width + 1) >> 1) * ((height + 1) >> 1))
+ return AVERROR_INVALIDDATA;
+ codec47_comp1(ctx, dst, width, height, width);
+ break;
+
+ default:
+ avpriv_report_missing_feature(ctx->avctx,
+ "Subcodec 48 compression %d", compr);
+ return AVERROR_PATCHWELCOME;
+ }
+ ctx->rotate_code = 1; // swap frm[0] and frm[2]
+ ctx->prev_seq = seq;
+ return 0;
+}
+
static int process_frame_obj(SANMVideoContext *ctx)
{
uint16_t codec = bytestream2_get_le16u(&ctx->gb);
@@ -1030,6 +1251,8 @@ static int process_frame_obj(SANMVideoContext *ctx)
return old_codec37(ctx, top, left, w, h);
case 47:
return old_codec47(ctx, top, left, w, h);
+ case 48:
+ return old_codec48(ctx, w, h);
default:
avpriv_request_sample(ctx->avctx, "Subcodec %d", codec);
return AVERROR_PATCHWELCOME;
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