X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fxan.c;h=4bf1d87f9db9dce199d491e06d42d17f3174cf47;hb=7dc827b7091b1ca85508b536fa776b49f363b0f4;hp=a1671e1cc59bbdf7227edf1de877acd56ca74253;hpb=d744801f1a7c65200a6ed207bb0dea197432288e;p=ffmpeg

diff --git a/libavcodec/xan.c b/libavcodec/xan.c
index a1671e1cc59..4bf1d87f9db 100644
--- a/libavcodec/xan.c
+++ b/libavcodec/xan.c
@@ -52,8 +52,7 @@
 typedef struct XanContext {
 
     AVCodecContext *avctx;
-    AVFrame last_frame;
-    AVFrame current_frame;
+    AVFrame *last_frame;
 
     const unsigned char *buf;
     int size;
@@ -72,6 +71,19 @@ typedef struct XanContext {
 
 } XanContext;
 
+static av_cold int xan_decode_end(AVCodecContext *avctx)
+{
+    XanContext *s = avctx->priv_data;
+
+    av_frame_free(&s->last_frame);
+
+    av_freep(&s->buffer1);
+    av_freep(&s->buffer2);
+    av_freep(&s->palettes);
+
+    return 0;
+}
+
 static av_cold int xan_decode_init(AVCodecContext *avctx)
 {
     XanContext *s = avctx->priv_data;
@@ -92,6 +104,12 @@ static av_cold int xan_decode_init(AVCodecContext *avctx)
         return AVERROR(ENOMEM);
     }
 
+    s->last_frame = av_frame_alloc();
+    if (!s->last_frame) {
+        xan_decode_end(avctx);
+        return AVERROR(ENOMEM);
+    }
+
     return 0;
 }
 
@@ -104,6 +122,7 @@ static int xan_huffman_decode(unsigned char *dest, int dest_len,
     int ptr_len = src_len - 1 - byte*2;
     unsigned char val = ival;
     unsigned char *dest_end = dest + dest_len;
+    unsigned char *dest_start = dest;
     GetBitContext gb;
 
     if (ptr_len < 0)
@@ -119,13 +138,13 @@ static int xan_huffman_decode(unsigned char *dest, int dest_len,
 
         if (val < 0x16) {
             if (dest >= dest_end)
-                return 0;
+                return dest_len;
             *dest++ = val;
             val = ival;
         }
     }
 
-    return 0;
+    return dest - dest_start;
 }
 
 /**
@@ -187,7 +206,7 @@ static void xan_unpack(unsigned char *dest, int dest_len,
     }
 }
 
-static inline void xan_wc3_output_pixel_run(XanContext *s,
+static inline void xan_wc3_output_pixel_run(XanContext *s, AVFrame *frame,
     const unsigned char *pixel_buffer, int x, int y, int pixel_count)
 {
     int stride;
@@ -197,8 +216,8 @@ static inline void xan_wc3_output_pixel_run(XanContext *s,
     int width = s->avctx->width;
     unsigned char *palette_plane;
 
-    palette_plane = s->current_frame.data[0];
-    stride = s->current_frame.linesize[0];
+    palette_plane = frame->data[0];
+    stride = frame->linesize[0];
     line_inc = stride - width;
     index = y * stride + x;
     current_x = x;
@@ -217,7 +236,8 @@ static inline void xan_wc3_output_pixel_run(XanContext *s,
     }
 }
 
-static inline void xan_wc3_copy_pixel_run(XanContext *s, int x, int y,
+static inline void xan_wc3_copy_pixel_run(XanContext *s, AVFrame *frame,
+                                          int x, int y,
                                           int pixel_count, int motion_x,
                                           int motion_y)
 {
@@ -232,11 +252,11 @@ static inline void xan_wc3_copy_pixel_run(XanContext *s, int x, int y,
         x + motion_x < 0 || x + motion_x >= s->avctx->width)
         return;
 
-    palette_plane = s->current_frame.data[0];
-    prev_palette_plane = s->last_frame.data[0];
+    palette_plane = frame->data[0];
+    prev_palette_plane = s->last_frame->data[0];
     if (!prev_palette_plane)
         prev_palette_plane = palette_plane;
-    stride = s->current_frame.linesize[0];
+    stride = frame->linesize[0];
     line_inc = stride - width;
     curframe_index = y * stride + x;
     curframe_x = x;
@@ -268,7 +288,8 @@ static inline void xan_wc3_copy_pixel_run(XanContext *s, int x, int y,
     }
 }
 
-static int xan_wc3_decode_frame(XanContext *s) {
+static int xan_wc3_decode_frame(XanContext *s, AVFrame *frame)
+{
 
     int width  = s->avctx->width;
     int height = s->avctx->height;
@@ -277,7 +298,7 @@ static int xan_wc3_decode_frame(XanContext *s) {
     unsigned char flag = 0;
     int size = 0;
     int motion_x, motion_y;
-    int x, y;
+    int x, y, ret;
 
     unsigned char *opcode_buffer = s->buffer1;
     unsigned char *opcode_buffer_end = s->buffer1 + s->buffer1_size;
@@ -286,8 +307,8 @@ static int xan_wc3_decode_frame(XanContext *s) {
 
     /* pointers to segments inside the compressed chunk */
     const unsigned char *huffman_segment;
-    const unsigned char *size_segment;
-    const unsigned char *vector_segment;
+    GetByteContext       size_segment;
+    GetByteContext       vector_segment;
     const unsigned char *imagedata_segment;
     int huffman_offset, size_offset, vector_offset, imagedata_offset,
         imagedata_size;
@@ -307,13 +328,14 @@ static int xan_wc3_decode_frame(XanContext *s) {
         return AVERROR_INVALIDDATA;
 
     huffman_segment   = s->buf + huffman_offset;
-    size_segment      = s->buf + size_offset;
-    vector_segment    = s->buf + vector_offset;
+    bytestream2_init(&size_segment,   s->buf + size_offset,   s->size - size_offset);
+    bytestream2_init(&vector_segment, s->buf + vector_offset, s->size - vector_offset);
     imagedata_segment = s->buf + imagedata_offset;
 
-    if (xan_huffman_decode(opcode_buffer, opcode_buffer_size,
-                           huffman_segment, s->size - huffman_offset) < 0)
+    if ((ret = xan_huffman_decode(opcode_buffer, opcode_buffer_size,
+                                  huffman_segment, s->size - huffman_offset)) < 0)
         return AVERROR_INVALIDDATA;
+    opcode_buffer_end = opcode_buffer + ret;
 
     if (imagedata_segment[0] == 2) {
         xan_unpack(s->buffer2, s->buffer2_size,
@@ -360,19 +382,17 @@ static int xan_wc3_decode_frame(XanContext *s) {
 
         case 9:
         case 19:
-            size = *size_segment++;
+            size = bytestream2_get_byte(&size_segment);
             break;
 
         case 10:
         case 20:
-            size = AV_RB16(&size_segment[0]);
-            size_segment += 2;
+            size = bytestream2_get_be16(&size_segment);
             break;
 
         case 11:
         case 21:
-            size = AV_RB24(size_segment);
-            size_segment += 3;
+            size = bytestream2_get_be24(&size_segment);
             break;
         }
 
@@ -383,23 +403,23 @@ static int xan_wc3_decode_frame(XanContext *s) {
             flag ^= 1;
             if (flag) {
                 /* run of (size) pixels is unchanged from last frame */
-                xan_wc3_copy_pixel_run(s, x, y, size, 0, 0);
+                xan_wc3_copy_pixel_run(s, frame, x, y, size, 0, 0);
             } else {
                 /* output a run of pixels from imagedata_buffer */
                 if (imagedata_size < size)
                     break;
-                xan_wc3_output_pixel_run(s, imagedata_buffer, x, y, size);
+                xan_wc3_output_pixel_run(s, frame, imagedata_buffer, x, y, size);
                 imagedata_buffer += size;
                 imagedata_size -= size;
             }
         } else {
             /* run-based motion compensation from last frame */
-            motion_x = sign_extend(*vector_segment >> 4,  4);
-            motion_y = sign_extend(*vector_segment & 0xF, 4);
-            vector_segment++;
+            uint8_t vector = bytestream2_get_byte(&vector_segment);
+            motion_x = sign_extend(vector >> 4,  4);
+            motion_y = sign_extend(vector & 0xF, 4);
 
             /* copy a run of pixels from the previous frame */
-            xan_wc3_copy_pixel_run(s, x, y, size, motion_x, motion_y);
+            xan_wc3_copy_pixel_run(s, frame, x, y, size, motion_x, motion_y);
 
             flag = 0;
         }
@@ -499,6 +519,7 @@ static int xan_decode_frame(AVCodecContext *avctx,
                             void *data, int *got_frame,
                             AVPacket *avpkt)
 {
+    AVFrame *frame = data;
     const uint8_t *buf = avpkt->data;
     int ret, buf_size = avpkt->size;
     XanContext *s = avctx->priv_data;
@@ -563,57 +584,36 @@ static int xan_decode_frame(AVCodecContext *avctx,
         return AVERROR_INVALIDDATA;
     }
 
-    if ((ret = ff_get_buffer(avctx, &s->current_frame))) {
+    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF))) {
         av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
         return ret;
     }
-    s->current_frame.reference = 3;
 
     if (!s->frame_size)
-        s->frame_size = s->current_frame.linesize[0] * s->avctx->height;
+        s->frame_size = frame->linesize[0] * s->avctx->height;
 
-    memcpy(s->current_frame.data[1],
+    memcpy(frame->data[1],
            s->palettes + s->cur_palette * AVPALETTE_COUNT, AVPALETTE_SIZE);
 
     s->buf = ctx.buffer;
     s->size = buf_size;
 
-    if (xan_wc3_decode_frame(s) < 0)
+    if (xan_wc3_decode_frame(s, frame) < 0)
         return AVERROR_INVALIDDATA;
 
-    /* release the last frame if it is allocated */
-    if (s->last_frame.data[0])
-        avctx->release_buffer(avctx, &s->last_frame);
+    av_frame_unref(s->last_frame);
+    if ((ret = av_frame_ref(s->last_frame, frame)) < 0)
+        return ret;
 
     *got_frame = 1;
-    *(AVFrame*)data = s->current_frame;
-
-    /* shuffle frames */
-    FFSWAP(AVFrame, s->current_frame, s->last_frame);
 
     /* always report that the buffer was completely consumed */
     return buf_size;
 }
 
-static av_cold int xan_decode_end(AVCodecContext *avctx)
-{
-    XanContext *s = avctx->priv_data;
-
-    /* release the frames */
-    if (s->last_frame.data[0])
-        avctx->release_buffer(avctx, &s->last_frame);
-    if (s->current_frame.data[0])
-        avctx->release_buffer(avctx, &s->current_frame);
-
-    av_freep(&s->buffer1);
-    av_freep(&s->buffer2);
-    av_freep(&s->palettes);
-
-    return 0;
-}
-
 AVCodec ff_xan_wc3_decoder = {
     .name           = "xan_wc3",
+    .long_name      = NULL_IF_CONFIG_SMALL("Wing Commander III / Xan"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_XAN_WC3,
     .priv_data_size = sizeof(XanContext),
@@ -621,5 +621,4 @@ AVCodec ff_xan_wc3_decoder = {
     .close          = xan_decode_end,
     .decode         = xan_decode_frame,
     .capabilities   = CODEC_CAP_DR1,
-    .long_name      = NULL_IF_CONFIG_SMALL("Wing Commander III / Xan"),
 };