svq1: replace struct svq1_frame_size with an array.
[ffmpeg.git] / libavcodec / gifdec.c
index 6ae0bdd..2a962e5 100644 (file)
@@ -1,32 +1,32 @@
 /*
  * GIF decoder
- * Copyright (c) 2003 Fabrice Bellard.
- * Copyright (c) 2006 Baptiste Coudurier.
+ * Copyright (c) 2003 Fabrice Bellard
+ * Copyright (c) 2006 Baptiste Coudurier
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
- * FFmpeg is distributed in the hope that it will be useful,
+ * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 //#define DEBUG
 
+#include "libavutil/imgutils.h"
 #include "avcodec.h"
 #include "bytestream.h"
-
-#define MAXBITS                 12
-#define SIZTABLE                (1<<MAXBITS)
+#include "internal.h"
+#include "lzw.h"
 
 #define GCE_DISPOSAL_NONE       0
 #define GCE_DISPOSAL_INPLACE    1
 #define GCE_DISPOSAL_RESTORE    3
 
 typedef struct GifState {
+    AVFrame picture;
     int screen_width;
     int screen_height;
     int bits_per_pixel;
     int background_color_index;
     int transparent_color_index;
     int color_resolution;
-    uint8_t *image_buf;
-    int image_linesize;
-    uint32_t image_palette[256];
-    int pix_fmt;
+    uint32_t *image_palette;
 
     /* after the frame is displayed, the disposal method is used */
     int gce_disposal;
@@ -51,181 +49,25 @@ typedef struct GifState {
     int gce_delay;
 
     /* LZW compatible decoder */
-    uint8_t *bytestream;
-    int eob_reached;
-    uint8_t *pbuf, *ebuf;
-    int bbits;
-    unsigned int bbuf;
-
-    int cursize;                /* The current code size */
-    int curmask;
-    int codesize;
-    int clear_code;
-    int end_code;
-    int newcodes;               /* First available code */
-    int top_slot;               /* Highest code for current size */
-    int slot;                   /* Last read code */
-    int fc, oc;
-    uint8_t *sp;
-    uint8_t stack[SIZTABLE];
-    uint8_t suffix[SIZTABLE];
-    uint16_t prefix[SIZTABLE];
+    const uint8_t *bytestream;
+    const uint8_t *bytestream_end;
+    LZWState *lzw;
 
     /* aux buffers */
     uint8_t global_palette[256 * 3];
     uint8_t local_palette[256 * 3];
-    uint8_t buf[256];
+
+  AVCodecContext* avctx;
 } GifState;
 
 static const uint8_t gif87a_sig[6] = "GIF87a";
 static const uint8_t gif89a_sig[6] = "GIF89a";
 
-static const uint16_t mask[17] =
-{
-    0x0000, 0x0001, 0x0003, 0x0007,
-    0x000F, 0x001F, 0x003F, 0x007F,
-    0x00FF, 0x01FF, 0x03FF, 0x07FF,
-    0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF
-};
-
-static void GLZWDecodeInit(GifState * s, int csize)
-{
-    /* read buffer */
-    s->eob_reached = 0;
-    s->pbuf = s->buf;
-    s->ebuf = s->buf;
-    s->bbuf = 0;
-    s->bbits = 0;
-
-    /* decoder */
-    s->codesize = csize;
-    s->cursize = s->codesize + 1;
-    s->curmask = mask[s->cursize];
-    s->top_slot = 1 << s->cursize;
-    s->clear_code = 1 << s->codesize;
-    s->end_code = s->clear_code + 1;
-    s->slot = s->newcodes = s->clear_code + 2;
-    s->oc = s->fc = 0;
-    s->sp = s->stack;
-}
-
-/* XXX: optimize */
-static inline int GetCode(GifState * s)
-{
-    int c, sizbuf;
-    uint8_t *ptr;
-
-    while (s->bbits < s->cursize) {
-        ptr = s->pbuf;
-        if (ptr >= s->ebuf) {
-            if (!s->eob_reached) {
-                sizbuf = bytestream_get_byte(&s->bytestream);
-                s->ebuf = s->buf + sizbuf;
-                s->pbuf = s->buf;
-                if (sizbuf > 0) {
-                    bytestream_get_buffer(&s->bytestream, s->buf, sizbuf);
-                } else {
-                    s->eob_reached = 1;
-                }
-            }
-            ptr = s->pbuf;
-        }
-        s->bbuf |= ptr[0] << s->bbits;
-        ptr++;
-        s->pbuf = ptr;
-        s->bbits += 8;
-    }
-    c = s->bbuf & s->curmask;
-    s->bbuf >>= s->cursize;
-    s->bbits -= s->cursize;
-    return c;
-}
-
-/* NOTE: the algorithm here is inspired from the LZW GIF decoder
-   written by Steven A. Bennett in 1987. */
-/* return the number of byte decoded */
-static int GLZWDecode(GifState * s, uint8_t * buf, int len)
-{
-    int l, c, code, oc, fc;
-    uint8_t *sp;
-
-    if (s->end_code < 0)
-        return 0;
-
-    l = len;
-    sp = s->sp;
-    oc = s->oc;
-    fc = s->fc;
-
-    while (sp > s->stack) {
-        *buf++ = *(--sp);
-        if ((--l) == 0)
-            goto the_end;
-    }
-
-    for (;;) {
-        c = GetCode(s);
-        if (c == s->end_code) {
-            s->end_code = -1;
-            break;
-        } else if (c == s->clear_code) {
-            s->cursize = s->codesize + 1;
-            s->curmask = mask[s->cursize];
-            s->slot = s->newcodes;
-            s->top_slot = 1 << s->cursize;
-            while ((c = GetCode(s)) == s->clear_code);
-            if (c == s->end_code) {
-                s->end_code = -1;
-                break;
-            }
-            /* test error */
-            if (c >= s->slot)
-                c = 0;
-            fc = oc = c;
-            *buf++ = c;
-            if ((--l) == 0)
-                break;
-        } else {
-            code = c;
-            if (code >= s->slot) {
-                *sp++ = fc;
-                code = oc;
-            }
-            while (code >= s->newcodes) {
-                *sp++ = s->suffix[code];
-                code = s->prefix[code];
-            }
-            *sp++ = code;
-            if (s->slot < s->top_slot) {
-                s->suffix[s->slot] = fc = code;
-                s->prefix[s->slot++] = oc;
-                oc = c;
-            }
-            if (s->slot >= s->top_slot) {
-                if (s->cursize < MAXBITS) {
-                    s->top_slot <<= 1;
-                    s->curmask = mask[++s->cursize];
-                }
-            }
-            while (sp > s->stack) {
-                *buf++ = *(--sp);
-                if ((--l) == 0)
-                    goto the_end;
-            }
-        }
-    }
-  the_end:
-    s->sp = sp;
-    s->oc = oc;
-    s->fc = fc;
-    return len - l;
-}
-
 static int gif_read_image(GifState *s)
 {
     int left, top, width, height, bits_per_pixel, code_size, flags;
-    int is_interleaved, has_local_palette, y, x, pass, y1, linesize, n, i;
-    uint8_t *ptr, *line, *d, *spal, *palette, *sptr, *ptr1;
+    int is_interleaved, has_local_palette, y, pass, y1, linesize, n, i;
+    uint8_t *ptr, *spal, *palette, *ptr1;
 
     left = bytestream_get_le16(&s->bytestream);
     top = bytestream_get_le16(&s->bytestream);
@@ -235,9 +77,8 @@ static int gif_read_image(GifState *s)
     is_interleaved = flags & 0x40;
     has_local_palette = flags & 0x80;
     bits_per_pixel = (flags & 0x07) + 1;
-#ifdef DEBUG
-    printf("gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height);
-#endif
+
+    av_dlog(s->avctx, "gif: image x=%d y=%d w=%d h=%d\n", left, top, width, height);
 
     if (has_local_palette) {
         bytestream_get_buffer(&s->bytestream, s->local_palette, 3 * (1 << bits_per_pixel));
@@ -250,35 +91,34 @@ static int gif_read_image(GifState *s)
     /* verify that all the image is inside the screen dimensions */
     if (left + width > s->screen_width ||
         top + height > s->screen_height)
-        return -EINVAL;
+        return AVERROR(EINVAL);
 
     /* build the palette */
-        n = (1 << bits_per_pixel);
-        spal = palette;
-        for(i = 0; i < n; i++) {
-            s->image_palette[i] = (0xff << 24) |
-                (spal[0] << 16) | (spal[1] << 8) | (spal[2]);
-            spal += 3;
-        }
-        for(; i < 256; i++)
-            s->image_palette[i] = (0xff << 24);
-        /* handle transparency */
-        if (s->transparent_color_index >= 0)
-            s->image_palette[s->transparent_color_index] = 0;
-        line = NULL;
+    n = (1 << bits_per_pixel);
+    spal = palette;
+    for(i = 0; i < n; i++) {
+        s->image_palette[i] = (0xffu << 24) | AV_RB24(spal);
+        spal += 3;
+    }
+    for(; i < 256; i++)
+        s->image_palette[i] = (0xffu << 24);
+    /* handle transparency */
+    if (s->transparent_color_index >= 0)
+        s->image_palette[s->transparent_color_index] = 0;
 
     /* now get the image data */
     code_size = bytestream_get_byte(&s->bytestream);
-    GLZWDecodeInit(s, code_size);
+    ff_lzw_decode_init(s->lzw, code_size, s->bytestream,
+                       s->bytestream_end - s->bytestream, FF_LZW_GIF);
 
     /* read all the image */
-    linesize = s->image_linesize;
-    ptr1 = s->image_buf + top * linesize + (left * 3);
+    linesize = s->picture.linesize[0];
+    ptr1 = s->picture.data[0] + top * linesize + left;
     ptr = ptr1;
     pass = 0;
     y1 = 0;
     for (y = 0; y < height; y++) {
-            GLZWDecode(s, ptr, width);
+        ff_lzw_decode(s->lzw, ptr, width);
         if (is_interleaved) {
             switch(pass) {
             default:
@@ -287,11 +127,8 @@ static int gif_read_image(GifState *s)
                 y1 += 8;
                 ptr += linesize * 8;
                 if (y1 >= height) {
-                    y1 = 4;
-                    if (pass == 0)
-                        ptr = ptr1 + linesize * 4;
-                    else
-                        ptr = ptr1 + linesize * 2;
+                    y1 = pass ? 2 : 4;
+                    ptr = ptr1 + linesize * y1;
                     pass++;
                 }
                 break;
@@ -313,11 +150,9 @@ static int gif_read_image(GifState *s)
             ptr += linesize;
         }
     }
-    av_free(line);
-
     /* read the garbage data until end marker is found */
-    while (!s->eob_reached)
-        GetCode(s);
+    ff_lzw_decode_tail(s->lzw);
+    s->bytestream = ff_lzw_cur_ptr(s->lzw);
     return 0;
 }
 
@@ -328,9 +163,9 @@ static int gif_read_extension(GifState *s)
     /* extension */
     ext_code = bytestream_get_byte(&s->bytestream);
     ext_len = bytestream_get_byte(&s->bytestream);
-#ifdef DEBUG
-    printf("gif: ext_code=0x%x len=%d\n", ext_code, ext_len);
-#endif
+
+    av_dlog(s->avctx, "gif: ext_code=0x%x len=%d\n", ext_code, ext_len);
+
     switch(ext_code) {
     case 0xf9:
         if (ext_len != 4)
@@ -344,11 +179,11 @@ static int gif_read_extension(GifState *s)
         else
             s->transparent_color_index = -1;
         s->gce_disposal = (gce_flags >> 2) & 0x7;
-#ifdef DEBUG
-        printf("gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
+
+        av_dlog(s->avctx, "gif: gce_flags=%x delay=%d tcolor=%d disposal=%d\n",
                gce_flags, s->gce_delay,
                s->transparent_color_index, s->gce_disposal);
-#endif
+
         ext_len = bytestream_get_byte(&s->bytestream);
         break;
     }
@@ -359,9 +194,8 @@ static int gif_read_extension(GifState *s)
         for (i = 0; i < ext_len; i++)
             bytestream_get_byte(&s->bytestream);
         ext_len = bytestream_get_byte(&s->bytestream);
-#ifdef DEBUG
-        printf("gif: ext_len1=%d\n", ext_len);
-#endif
+
+        av_dlog(s->avctx, "gif: ext_len1=%d\n", ext_len);
     }
     return 0;
 }
@@ -369,14 +203,17 @@ static int gif_read_extension(GifState *s)
 static int gif_read_header1(GifState *s)
 {
     uint8_t sig[6];
-    int ret, v, n;
+    int v, n;
     int has_global_palette;
 
+    if (s->bytestream_end < s->bytestream + 13)
+        return AVERROR_INVALIDDATA;
+
     /* read gif signature */
     bytestream_get_buffer(&s->bytestream, sig, 6);
     if (memcmp(sig, gif87a_sig, 6) != 0 &&
         memcmp(sig, gif89a_sig, 6) != 0)
-        return -1;
+        return AVERROR_INVALIDDATA;
 
     /* read screen header */
     s->transparent_color_index = -1;
@@ -385,7 +222,7 @@ static int gif_read_header1(GifState *s)
     if(   (unsigned)s->screen_width  > 32767
        || (unsigned)s->screen_height > 32767){
         av_log(NULL, AV_LOG_ERROR, "picture size too large\n");
-        return -1;
+        return AVERROR_INVALIDDATA;
     }
 
     v = bytestream_get_byte(&s->bytestream);
@@ -394,13 +231,15 @@ static int gif_read_header1(GifState *s)
     s->bits_per_pixel = (v & 0x07) + 1;
     s->background_color_index = bytestream_get_byte(&s->bytestream);
     bytestream_get_byte(&s->bytestream);                /* ignored */
-#ifdef DEBUG
-    printf("gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
+
+    av_dlog(s->avctx, "gif: screen_w=%d screen_h=%d bpp=%d global_palette=%d\n",
            s->screen_width, s->screen_height, s->bits_per_pixel,
            has_global_palette);
-#endif
+
     if (has_global_palette) {
         n = 1 << s->bits_per_pixel;
+        if (s->bytestream_end < s->bytestream + n * 3)
+            return AVERROR_INVALIDDATA;
         bytestream_get_buffer(&s->bytestream, s->global_palette, n * 3);
     }
     return 0;
@@ -408,88 +247,95 @@ static int gif_read_header1(GifState *s)
 
 static int gif_parse_next_image(GifState *s)
 {
-    int ret, code;
+    while (s->bytestream < s->bytestream_end) {
+        int code = bytestream_get_byte(&s->bytestream);
+        int ret;
+
+        av_dlog(s->avctx, "gif: code=%02x '%c'\n", code, code);
 
-    for (;;) {
-        code = bytestream_get_byte(&s->bytestream);
-#ifdef DEBUG
-        printf("gif: code=%02x '%c'\n", code, code);
-#endif
         switch (code) {
         case ',':
-            if (gif_read_image(s) < 0)
-                return -1;
-            ret = 0;
-            goto the_end;
-        case ';':
-            /* end of image */
-            ret = -1;
-            goto the_end;
+            return gif_read_image(s);
         case '!':
-            if (gif_read_extension(s) < 0)
-                return -1;
+            if ((ret = gif_read_extension(s)) < 0)
+                return ret;
             break;
-        case EOF:
+        case ';':
+            /* end of image */
         default:
-            /* error or errneous EOF */
-            ret = -1;
-            goto the_end;
+            /* error or erroneous EOF */
+            return AVERROR_INVALIDDATA;
         }
     }
-  the_end:
-    return ret;
+    return AVERROR_INVALIDDATA;
 }
 
-static int gif_decode_init(AVCodecContext *avctx)
+static av_cold int gif_decode_init(AVCodecContext *avctx)
 {
     GifState *s = avctx->priv_data;
 
+    s->avctx = avctx;
+
+    avcodec_get_frame_defaults(&s->picture);
+    avctx->coded_frame= &s->picture;
+    s->picture.data[0] = NULL;
+    ff_lzw_decode_open(&s->lzw);
     return 0;
 }
 
-static int gif_decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)
+static int gif_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
+                            AVPacket *avpkt)
 {
+    const uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
     GifState *s = avctx->priv_data;
     AVFrame *picture = data;
     int ret;
 
     s->bytestream = buf;
-    if (gif_read_header1(s) < 0)
-        return -1;
-
-    /* allocate image buffer */
-    s->image_linesize = s->screen_width * 3;
-    s->image_buf = av_malloc(s->screen_height * s->image_linesize);
-    if (!s->image_buf)
-        return -ENOMEM;
-    s->pix_fmt = PIX_FMT_PAL8;
-    /* now we are ready: build format streams */
-
-    /* XXX: check if screen size is always valid */
-    avctx->width = s->screen_width;
-    avctx->height = s->screen_height;
-    avctx->pix_fmt = PIX_FMT_PAL8;
+    s->bytestream_end = buf + buf_size;
+    if ((ret = gif_read_header1(s)) < 0)
+        return ret;
 
+    avctx->pix_fmt = AV_PIX_FMT_PAL8;
+    if ((ret = av_image_check_size(s->screen_width, s->screen_height, 0, avctx)) < 0)
+        return ret;
+    avcodec_set_dimensions(avctx, s->screen_width, s->screen_height);
+
+    if (s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
+    if ((ret = ff_get_buffer(avctx, &s->picture)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+    s->image_palette = (uint32_t *)s->picture.data[1];
     ret = gif_parse_next_image(s);
     if (ret < 0)
         return ret;
 
-    picture->data[0] = s->image_buf;
-    picture->linesize[0] = s->image_linesize;
-    picture->data[1] = s->image_palette;
-    picture->linesize[1] = 4;
+    *picture = s->picture;
+    *got_frame = 1;
+    return s->bytestream - buf;
+}
+
+static av_cold int gif_decode_close(AVCodecContext *avctx)
+{
+    GifState *s = avctx->priv_data;
 
-    *data_size = sizeof(AVPicture);
+    ff_lzw_decode_close(&s->lzw);
+    if(s->picture.data[0])
+        avctx->release_buffer(avctx, &s->picture);
     return 0;
 }
 
-AVCodec gif_decoder = {
-    "gif",
-    CODEC_TYPE_VIDEO,
-    CODEC_ID_GIF,
-    sizeof(GifState),
-    gif_decode_init,
-    NULL,
-    NULL,
-    gif_decode_frame,
+AVCodec ff_gif_decoder = {
+    .name           = "gif",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_GIF,
+    .priv_data_size = sizeof(GifState),
+    .init           = gif_decode_init,
+    .close          = gif_decode_close,
+    .decode         = gif_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
+    .long_name      = NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
 };