[FFmpeg-devel] [PATCH] libavcodec/sanm: SMUSH codec48 decoder
Manuel Lauss
manuel.lauss at gmail.com
Thu Jan 2 10:16:26 EET 2025
Hello,
Ping? With this patch the 2 sample files at
http://samples.mplayerhq.hu/game-formats/la-san/jediknight-sith/ play
just fine.
Thanks,
Manuel
On Mon, Dec 16, 2024 at 5:08 PM Manuel Lauss <manuel.lauss at gmail.com> wrote:
>
> 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>
> ---
> 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;
> --
> 2.47.1
>
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