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| author | Manuel Lauss <manuel.lauss@gmail.com> | 2025-05-30 13:10:47 +0200 |
|---|---|---|
| committer | Manuel Lauss <manuel.lauss@gmail.com> | 2025-06-06 22:07:15 +0200 |
| commit | d9797544b45a6f2fbd334dd41194b95026555297 (patch) | |
| tree | ef5bb7c40809f62ba82d11536df1d27666cac521 | |
| parent | b7662ddd15dc8f6db38065465a7a1087e0cae0ff (diff) | |
| download | ffmpeg-d9797544b45a6f2fbd334dd41194b95026555297.tar.gz | |
avcodec/sanm: codec31/32 support
codec31/32 are similar to codec1/3 (RLE coding) but with two 4-bit pixels
per byte; they are only used in the Sega-CD release of Rebel Assault 1.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
| -rw-r--r-- | libavcodec/sanm.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/libavcodec/sanm.c b/libavcodec/sanm.c index 417199095d..642ef02bff 100644 --- a/libavcodec/sanm.c +++ b/libavcodec/sanm.c @@ -909,6 +909,62 @@ 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) { @@ -1689,6 +1745,9 @@ 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: |