dxtory: Unify and rework the decoding routines

Do not make many assumption on the dimension of the slices and just
try to decode additional lines if there is enough data left.

Decodes all the samples kindly provided by ultramage.

1 files changed, 165 insertions, 239 deletions

diff --git a/libavcodec/dxtory.c b/libavcodec/dxtory.c
index dd0d512931..0a6f331c4b 100644
--- a/libavcodec/dxtory.c
+++ b/libavcodec/dxtory.c
@@ -233,7 +233,7 @@ static int load_buffer(AVCodecContext *avctx,
         return AVERROR_INVALIDDATA;
     }
 
-    if (!*nslices || avctx->height % *nslices) {
+    if (!*nslices) {
         avpriv_request_sample(avctx, "%d slices for %dx%d", *nslices,
                               avctx->width, avctx->height);
         return AVERROR_PATCHWELCOME;
@@ -260,142 +260,182 @@ static inline uint8_t decode_sym_565(GetBitContext *gb, uint8_t lru[8],
     return val;
 }
 
-static int dx2_decode_slice_565(GetBitContext *gb, int width, int height,
-                                uint8_t *dst, int stride, int is_565)
-{
-    int x, y;
-    int r, g, b;
-    uint8_t lru[3][8];
-
-    memcpy(lru[0], def_lru_555, 8 * sizeof(*def_lru));
-    memcpy(lru[1], is_565 ? def_lru_565 : def_lru_555, 8 * sizeof(*def_lru));
-    memcpy(lru[2], def_lru_555, 8 * sizeof(*def_lru));
-
-    for (y = 0; y < height; y++) {
-        for (x = 0; x < width; x++) {
-            b = decode_sym_565(gb, lru[0], 5);
-            g = decode_sym_565(gb, lru[1], is_565 ? 6 : 5);
-            r = decode_sym_565(gb, lru[2], 5);
-            dst[x * 3 + 0] = (r << 3) | (r >> 2);
-            dst[x * 3 + 1] = is_565 ? (g << 2) | (g >> 4) : (g << 3) | (g >> 2);
-            dst[x * 3 + 2] = (b << 3) | (b >> 2);
-        }
+typedef int (*decode_slice_func)(GetBitContext *gb, AVFrame *frame,
+                                 int line, int height, uint8_t lru[3][8]);
 
-        dst += stride;
-    }
-
-    return 0;
-}
+typedef void (*setup_lru_func)(uint8_t lru[3][8]);
 
-static int dxtory_decode_v2_565(AVCodecContext *avctx, AVFrame *pic,
-                                const uint8_t *src, int src_size, int is_565)
+static int dxtory_decode_v2(AVCodecContext *avctx, AVFrame *pic,
+                            const uint8_t *src, int src_size,
+                            decode_slice_func decode_slice,
+                            setup_lru_func setup_lru,
+                            enum AVPixelFormat fmt)
 {
     GetByteContext gb;
     GetBitContext  gb2;
-    int nslices, slice, slice_height;
+    int nslices, slice, line = 0;
     uint32_t off, slice_size;
-    uint8_t *dst;
+    uint8_t lru[3][8];
     int ret;
 
     ret = load_buffer(avctx, src, src_size, &gb, &nslices, &off);
     if (ret < 0)
         return ret;
 
-    slice_height = avctx->height / nslices;
-    avctx->pix_fmt = AV_PIX_FMT_RGB24;
+    avctx->pix_fmt = fmt;
     if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
         return ret;
 
-    dst = pic->data[0];
     for (slice = 0; slice < nslices; slice++) {
         slice_size = bytestream2_get_le32(&gb);
 
+        setup_lru(lru);
+
         ret = check_slice_size(avctx, src, src_size, slice_size, off);
         if (ret < 0)
             return ret;
 
         init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
-        dx2_decode_slice_565(&gb2, avctx->width, slice_height, dst,
-                             pic->linesize[0], is_565);
 
-        dst += pic->linesize[0] * slice_height;
+        line += decode_slice(&gb2, pic, line, avctx->height - line, lru);
+
         off += slice_size;
     }
 
+    if (avctx->height - line) {
+        av_log(avctx, AV_LOG_VERBOSE,
+               "Not enough slice data available, "
+               "cropping the frame by %d pixels\n",
+                avctx->height - line);
+        avctx->height = line;
+    }
+
     return 0;
 }
 
-static int dx2_decode_slice_rgb(GetBitContext *gb, int width, int height,
-                                uint8_t *dst, int stride)
+av_always_inline
+static int dx2_decode_slice_5x5(GetBitContext *gb, AVFrame *frame,
+                                int line, int left, uint8_t lru[3][8],
+                                int is_565)
 {
-    int x, y, i;
-    uint8_t lru[3][8];
-
-    for (i = 0; i < 3; i++)
-        memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
+    int x, y;
+    int r, g, b;
+    int width    = frame->width;
+    int stride   = frame->linesize[0];
+    uint8_t *dst = frame->data[0] + stride * line;
 
-    for (y = 0; y < height; y++) {
+    for (y = 0; y < left && get_bits_left(gb) > 16; y++) {
         for (x = 0; x < width; x++) {
-            dst[x * 3 + 0] = decode_sym(gb, lru[0]);
-            dst[x * 3 + 1] = decode_sym(gb, lru[1]);
-            dst[x * 3 + 2] = decode_sym(gb, lru[2]);
+            b = decode_sym_565(gb, lru[0], 5);
+            g = decode_sym_565(gb, lru[1], is_565 ? 6 : 5);
+            r = decode_sym_565(gb, lru[2], 5);
+            dst[x * 3 + 0] = (r << 3) | (r >> 2);
+            dst[x * 3 + 1] = is_565 ? (g << 2) | (g >> 4) : (g << 3) | (g >> 2);
+            dst[x * 3 + 2] = (b << 3) | (b >> 2);
         }
 
         dst += stride;
     }
 
-    return 0;
+    return y;
 }
 
-static int dxtory_decode_v2_rgb(AVCodecContext *avctx, AVFrame *pic,
-                                const uint8_t *src, int src_size)
+static void setup_lru_555(uint8_t lru[3][8])
 {
-    GetByteContext gb;
-    GetBitContext  gb2;
-    int nslices, slice, slice_height;
-    uint32_t off, slice_size;
-    uint8_t *dst;
-    int ret;
+    memcpy(lru[0], def_lru_555, 8 * sizeof(*def_lru));
+    memcpy(lru[1], def_lru_555, 8 * sizeof(*def_lru));
+    memcpy(lru[2], def_lru_555, 8 * sizeof(*def_lru));
+}
 
-    ret = load_buffer(avctx, src, src_size, &gb, &nslices, &off);
-    if (ret < 0)
-        return ret;
+static void setup_lru_565(uint8_t lru[3][8])
+{
+    memcpy(lru[0], def_lru_555, 8 * sizeof(*def_lru));
+    memcpy(lru[1], def_lru_565, 8 * sizeof(*def_lru));
+    memcpy(lru[2], def_lru_555, 8 * sizeof(*def_lru));
+}
 
-    slice_height = avctx->height / nslices;
-    avctx->pix_fmt = AV_PIX_FMT_BGR24;
-    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
-        return ret;
+static int dx2_decode_slice_555(GetBitContext *gb, AVFrame *frame,
+                                int line, int left, uint8_t lru[3][8])
+{
+    return dx2_decode_slice_5x5(gb, frame, line, left, lru, 0);
+}
 
-    dst = pic->data[0];
-    for (slice = 0; slice < nslices; slice++) {
-        slice_size = bytestream2_get_le32(&gb);
+static int dx2_decode_slice_565(GetBitContext *gb, AVFrame *frame,
+                                int line, int left, uint8_t lru[3][8])
+{
+    return dx2_decode_slice_5x5(gb, frame, line, left, lru, 1);
+}
 
-        ret = check_slice_size(avctx, src, src_size, slice_size, off);
-        if (ret < 0)
-            return ret;
+static int dxtory_decode_v2_565(AVCodecContext *avctx, AVFrame *pic,
+                                const uint8_t *src, int src_size, int is_565)
+{
+    enum AVPixelFormat fmt = AV_PIX_FMT_RGB24;
+    if (is_565)
+        return dxtory_decode_v2(avctx, pic, src, src_size,
+                                dx2_decode_slice_565,
+                                setup_lru_565,
+                                fmt);
+    else
+        return dxtory_decode_v2(avctx, pic, src, src_size,
+                                dx2_decode_slice_555,
+                                setup_lru_555,
+                                fmt);
+}
 
-        init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
-        dx2_decode_slice_rgb(&gb2, avctx->width, slice_height, dst,
-                             pic->linesize[0]);
+static int dx2_decode_slice_rgb(GetBitContext *gb, AVFrame *frame,
+                                int line, int left, uint8_t lru[3][8])
+{
+    int x, y;
+    int width    = frame->width;
+    int stride   = frame->linesize[0];
+    uint8_t *dst = frame->data[0] + stride * line;
 
-        dst += pic->linesize[0] * slice_height;
-        off += slice_size;
+    for (y = 0; y < left && get_bits_left(gb) > 16; y++) {
+        for (x = 0; x < width; x++) {
+            dst[x * 3 + 0] = decode_sym(gb, lru[0]);
+            dst[x * 3 + 1] = decode_sym(gb, lru[1]);
+            dst[x * 3 + 2] = decode_sym(gb, lru[2]);
+        }
+
+        dst += stride;
     }
 
-    return 0;
+    return y;
 }
 
-static int dx2_decode_slice_410(GetBitContext *gb, int width, int height,
-                                uint8_t *Y, uint8_t *U, uint8_t *V,
-                                int ystride, int ustride, int vstride)
+static void default_setup_lru(uint8_t lru[3][8])
 {
-    int x, y, i, j;
-    uint8_t lru[3][8];
+    int i;
 
     for (i = 0; i < 3; i++)
         memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
+}
 
-    for (y = 0; y < height; y += 4) {
+static int dxtory_decode_v2_rgb(AVCodecContext *avctx, AVFrame *pic,
+                                const uint8_t *src, int src_size)
+{
+    return dxtory_decode_v2(avctx, pic, src, src_size,
+                            dx2_decode_slice_rgb,
+                            default_setup_lru,
+                            AV_PIX_FMT_BGR24);
+}
+
+static int dx2_decode_slice_410(GetBitContext *gb, AVFrame *frame,
+                                int line, int left,
+                                uint8_t lru[3][8])
+{
+    int x, y, i, j;
+    int width   = frame->width;
+
+    int ystride = frame->linesize[0];
+    int ustride = frame->linesize[1];
+    int vstride = frame->linesize[2];
+
+    uint8_t *Y  = frame->data[0] + ystride * line;
+    uint8_t *U  = frame->data[1] + (ustride >> 2) * line;
+    uint8_t *V  = frame->data[2] + (vstride >> 2) * line;
+
+    for (y = 0; y < left - 3 && get_bits_left(gb) > 16; y += 4) {
         for (x = 0; x < width; x += 4) {
             for (j = 0; j < 4; j++)
                 for (i = 0; i < 4; i++)
@@ -409,75 +449,37 @@ static int dx2_decode_slice_410(GetBitContext *gb, int width, int height,
         V += vstride;
     }
 
-    return 0;
+    return y;
 }
 
+
 static int dxtory_decode_v2_410(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
-    GetByteContext gb;
-    GetBitContext  gb2;
-    int nslices, slice, slice_height, ref_slice_height;
-    int cur_y, next_y;
-    uint32_t off, slice_size;
-    uint8_t *Y, *U, *V;
-    int ret;
-
-    ret = load_buffer(avctx, src, src_size, &gb, &nslices, &off);
-    if (ret < 0)
-        return ret;
-
-    ref_slice_height = avctx->height / nslices;
-    if ((avctx->width & 3) || (avctx->height & 3)) {
-        avpriv_request_sample(avctx, "Frame dimensions %dx%d",
-                              avctx->width, avctx->height);
-    }
-
-    avctx->pix_fmt = AV_PIX_FMT_YUV410P;
-    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
-        return ret;
+    return dxtory_decode_v2(avctx, pic, src, src_size,
+                            dx2_decode_slice_410,
+                            default_setup_lru,
+                            AV_PIX_FMT_YUV410P);
+}
 
-    Y = pic->data[0];
-    U = pic->data[1];
-    V = pic->data[2];
+static int dx2_decode_slice_420(GetBitContext *gb, AVFrame *frame,
+                                int line, int left,
+                                uint8_t lru[3][8])
+{
+    int x, y;
 
-    cur_y  = 0;
-    next_y = ref_slice_height;
-    for (slice = 0; slice < nslices; slice++) {
-        slice_size   = bytestream2_get_le32(&gb);
-        slice_height = (next_y & ~3) - (cur_y & ~3);
+    int width    = frame->width;
 
-        ret = check_slice_size(avctx, src, src_size, slice_size, off);
-        if (ret < 0)
-            return ret;
+    int ystride = frame->linesize[0];
+    int ustride = frame->linesize[1];
+    int vstride = frame->linesize[2];
 
-        init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
-        dx2_decode_slice_410(&gb2, avctx->width, slice_height, Y, U, V,
-                             pic->linesize[0], pic->linesize[1],
-                             pic->linesize[2]);
+    uint8_t *Y  = frame->data[0] + ystride * line;
+    uint8_t *U  = frame->data[1] + (ustride >> 1) * line;
+    uint8_t *V  = frame->data[2] + (vstride >> 1) * line;
 
-        Y += pic->linesize[0] *  slice_height;
-        U += pic->linesize[1] * (slice_height >> 2);
-        V += pic->linesize[2] * (slice_height >> 2);
-        off += slice_size;
-        cur_y   = next_y;
-        next_y += ref_slice_height;
-    }
 
-    return 0;
-}
-
-static int dx2_decode_slice_420(GetBitContext *gb, int width, int height,
-                                uint8_t *Y, uint8_t *U, uint8_t *V,
-                                int ystride, int ustride, int vstride)
-{
-    int x, y, i;
-    uint8_t lru[3][8];
-
-    for (i = 0; i < 3; i++)
-        memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
-
-    for (y = 0; y < height; y+=2) {
+    for (y = 0; y < left - 1 && get_bits_left(gb) > 16; y += 2) {
         for (x = 0; x < width; x += 2) {
             Y[x + 0 + 0 * ystride] = decode_sym(gb, lru[0]);
             Y[x + 1 + 0 * ystride] = decode_sym(gb, lru[0]);
@@ -492,75 +494,35 @@ static int dx2_decode_slice_420(GetBitContext *gb, int width, int height,
         V += vstride;
     }
 
-    return 0;
+    return y;
 }
 
 static int dxtory_decode_v2_420(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
-    GetByteContext gb;
-    GetBitContext  gb2;
-    int nslices, slice, slice_height, ref_slice_height;
-    int cur_y, next_y;
-    uint32_t off, slice_size;
-    uint8_t *Y, *U, *V;
-    int ret;
-
-    ret = load_buffer(avctx, src, src_size, &gb, &nslices, &off);
-    if (ret < 0)
-        return ret;
-
-    ref_slice_height = avctx->height / nslices;
-    if ((avctx->width & 1) || (avctx->height & 1)) {
-        avpriv_request_sample(avctx, "Frame dimensions %dx%d",
-                              avctx->width, avctx->height);
-    }
-
-    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
-    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
-        return ret;
-
-    Y = pic->data[0];
-    U = pic->data[1];
-    V = pic->data[2];
-
-    cur_y  = 0;
-    next_y = ref_slice_height;
-    for (slice = 0; slice < nslices; slice++) {
-        slice_size   = bytestream2_get_le32(&gb);
-        slice_height = (next_y & ~1) - (cur_y & ~1);
-
-        ret = check_slice_size(avctx, src, src_size, slice_size, off);
-        if (ret < 0)
-            return ret;
-
-        init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
-        dx2_decode_slice_420(&gb2, avctx->width, slice_height, Y, U, V,
-                             pic->linesize[0], pic->linesize[1],
-                             pic->linesize[2]);
-
-        Y += pic->linesize[0] *  slice_height;
-        U += pic->linesize[1] * (slice_height >> 1);
-        V += pic->linesize[2] * (slice_height >> 1);
-        off += slice_size;
-        cur_y   = next_y;
-        next_y += ref_slice_height;
-    }
-
-    return 0;
+    return dxtory_decode_v2(avctx, pic, src, src_size,
+                            dx2_decode_slice_420,
+                            default_setup_lru,
+                            AV_PIX_FMT_YUV420P);
 }
 
-static int dx2_decode_slice_444(GetBitContext *gb, int width, int height,
-                                uint8_t *Y, uint8_t *U, uint8_t *V,
-                                int ystride, int ustride, int vstride)
+static int dx2_decode_slice_444(GetBitContext *gb, AVFrame *frame,
+                                int line, int left,
+                                uint8_t lru[3][8])
 {
-    int x, y, i;
-    uint8_t lru[3][8];
+    int x, y;
 
-    for (i = 0; i < 3; i++)
-        memcpy(lru[i], def_lru, 8 * sizeof(*def_lru));
+    int width   = frame->width;
+
+    int ystride = frame->linesize[0];
+    int ustride = frame->linesize[1];
+    int vstride = frame->linesize[2];
+
+    uint8_t *Y  = frame->data[0] + ystride * line;
+    uint8_t *U  = frame->data[1] + ustride * line;
+    uint8_t *V  = frame->data[2] + vstride * line;
 
-    for (y = 0; y < height; y++) {
+    for (y = 0; y < left && get_bits_left(gb) > 16; y++) {
         for (x = 0; x < width; x++) {
             Y[x] = decode_sym(gb, lru[0]);
             U[x] = decode_sym(gb, lru[1]) ^ 0x80;
@@ -572,52 +534,16 @@ static int dx2_decode_slice_444(GetBitContext *gb, int width, int height,
         V += vstride;
     }
 
-    return 0;
+    return y;
 }
 
 static int dxtory_decode_v2_444(AVCodecContext *avctx, AVFrame *pic,
                                 const uint8_t *src, int src_size)
 {
-    GetByteContext gb;
-    GetBitContext  gb2;
-    int nslices, slice, slice_height;
-    uint32_t off, slice_size;
-    uint8_t *Y, *U, *V;
-    int ret;
-
-    ret = load_buffer(avctx, src, src_size, &gb, &nslices, &off);
-    if (ret < 0)
-        return ret;
-
-    slice_height = avctx->height / nslices;
-
-    avctx->pix_fmt = AV_PIX_FMT_YUV444P;
-    if ((ret = ff_get_buffer(avctx, pic, 0)) < 0)
-        return ret;
-
-    Y = pic->data[0];
-    U = pic->data[1];
-    V = pic->data[2];
-
-    for (slice = 0; slice < nslices; slice++) {
-        slice_size = bytestream2_get_le32(&gb);
-
-        ret = check_slice_size(avctx, src, src_size, slice_size, off);
-        if (ret < 0)
-            return ret;
-
-        init_get_bits(&gb2, src + off + 16, (slice_size - 16) * 8);
-        dx2_decode_slice_444(&gb2, avctx->width, slice_height, Y, U, V,
-                             pic->linesize[0], pic->linesize[1],
-                             pic->linesize[2]);
-
-        Y += pic->linesize[0] * slice_height;
-        U += pic->linesize[1] * slice_height;
-        V += pic->linesize[2] * slice_height;
-        off += slice_size;
-    }
-
-    return 0;
+    return dxtory_decode_v2(avctx, pic, src, src_size,
+                            dx2_decode_slice_444,
+                            default_setup_lru,
+                            AV_PIX_FMT_YUV444P);
 }
 
 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,