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ffmpeg.wasm-core
Commit 8febcb9f authored by Ronald S. Bultje's avatar Ronald S. Bultje
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smc: port to bytestream2 API. 

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
parent ba36f14e
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Showing with 32 additions and 42 deletions
libavcodec/smc.c
View file @ 8febcb9f
......@@ -34,6 +34,7 @@
#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "bytestream.h"
#define CPAIR 2
#define CQUAD 4
......@@ -46,8 +47,7 @@ typedef struct SmcContext {
AVCodecContext *avctx;
AVFrame frame;
const unsigned char *buf;
int size;
GetByteContext gb;
/* SMC color tables */
unsigned char color_pairs[COLORS_PER_TABLE * CPAIR];
......@@ -58,7 +58,7 @@ typedef struct SmcContext {
} SmcContext;
#define GET_BLOCK_COUNT() \
(opcode & 0x10) ? (1 + s->buf[stream_ptr++]) : 1 + (opcode & 0x0F);
(opcode & 0x10) ? (1 + bytestream2_get_byte(&s->gb)) : 1 + (opcode & 0x0F);
#define ADVANCE_BLOCK() \
{ \
......@@ -82,8 +82,8 @@ static void smc_decode_stream(SmcContext *s)
int height = s->avctx->height;
int stride = s->frame.linesize[0];
int i;
int stream_ptr = 0;
int chunk_size;
int buf_size = (int) (s->gb.buffer_end - s->gb.buffer_start);
unsigned char opcode;
int n_blocks;
unsigned int color_flags;
......@@ -113,24 +113,18 @@ static void smc_decode_stream(SmcContext *s)
/* make the palette available */
memcpy(s->frame.data[1], s->pal, AVPALETTE_SIZE);
chunk_size = AV_RB32(&s->buf[stream_ptr]) & 0x00FFFFFF;
stream_ptr += 4;
if (chunk_size != s->size)
bytestream2_skip(&s->gb, 1);
chunk_size = bytestream2_get_be24(&s->gb);
if (chunk_size != buf_size)
av_log(s->avctx, AV_LOG_INFO, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
chunk_size, s->size);
chunk_size, buf_size);
chunk_size = s->size;
chunk_size = buf_size;
total_blocks = ((s->avctx->width + 3) / 4) * ((s->avctx->height + 3) / 4);
/* traverse through the blocks */
while (total_blocks) {
/* sanity checks */
/* make sure stream ptr hasn't gone out of bounds */
if (stream_ptr > chunk_size) {
av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (stream ptr = %d, chunk size = %d)\n",
stream_ptr, chunk_size);
return;
}
/* make sure the row pointer hasn't gone wild */
if (row_ptr >= image_size) {
av_log(s->avctx, AV_LOG_INFO, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",
......@@ -138,7 +132,7 @@ static void smc_decode_stream(SmcContext *s)
return;
}
opcode = s->buf[stream_ptr++];
opcode = bytestream2_get_byte(&s->gb);
switch (opcode & 0xF0) {
/* skip n blocks */
case 0x00:
......@@ -158,7 +152,7 @@ static void smc_decode_stream(SmcContext *s)
if ((row_ptr == 0) && (pixel_ptr == 0)) {
av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",
opcode & 0xF0);
break;
return;
}
/* figure out where the previous block started */
......@@ -192,7 +186,7 @@ static void smc_decode_stream(SmcContext *s)
if ((row_ptr == 0) && (pixel_ptr < 2 * 4)) {
av_log(s->avctx, AV_LOG_INFO, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
opcode & 0xF0);
break;
return;
}
/* figure out where the previous 2 blocks started */
......@@ -233,7 +227,7 @@ static void smc_decode_stream(SmcContext *s)
case 0x60:
case 0x70:
n_blocks = GET_BLOCK_COUNT();
pixel = s->buf[stream_ptr++];
pixel = bytestream2_get_byte(&s->gb);
while (n_blocks--) {
block_ptr = row_ptr + pixel_ptr;
......@@ -257,7 +251,7 @@ static void smc_decode_stream(SmcContext *s)
/* fetch the next 2 colors from bytestream and store in next
* available entry in the color pair table */
for (i = 0; i < CPAIR; i++) {
pixel = s->buf[stream_ptr++];
pixel = bytestream2_get_byte(&s->gb);
color_table_index = CPAIR * color_pair_index + i;
s->color_pairs[color_table_index] = pixel;
}
......@@ -268,11 +262,10 @@ static void smc_decode_stream(SmcContext *s)
if (color_pair_index == COLORS_PER_TABLE)
color_pair_index = 0;
} else
color_table_index = CPAIR * s->buf[stream_ptr++];
color_table_index = CPAIR * bytestream2_get_byte(&s->gb);
while (n_blocks--) {
color_flags = AV_RB16(&s->buf[stream_ptr]);
stream_ptr += 2;
color_flags = bytestream2_get_be16(&s->gb);
flag_mask = 0x8000;
block_ptr = row_ptr + pixel_ptr;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
......@@ -300,7 +293,7 @@ static void smc_decode_stream(SmcContext *s)
/* fetch the next 4 colors from bytestream and store in next
* available entry in the color quad table */
for (i = 0; i < CQUAD; i++) {
pixel = s->buf[stream_ptr++];
pixel = bytestream2_get_byte(&s->gb);
color_table_index = CQUAD * color_quad_index + i;
s->color_quads[color_table_index] = pixel;
}
......@@ -311,11 +304,10 @@ static void smc_decode_stream(SmcContext *s)
if (color_quad_index == COLORS_PER_TABLE)
color_quad_index = 0;
} else
color_table_index = CQUAD * s->buf[stream_ptr++];
color_table_index = CQUAD * bytestream2_get_byte(&s->gb);
while (n_blocks--) {
color_flags = AV_RB32(&s->buf[stream_ptr]);
stream_ptr += 4;
color_flags = bytestream2_get_be32(&s->gb);
/* flag mask actually acts as a bit shift count here */
flag_mask = 30;
block_ptr = row_ptr + pixel_ptr;
......@@ -342,7 +334,7 @@ static void smc_decode_stream(SmcContext *s)
/* fetch the next 8 colors from bytestream and store in next
* available entry in the color octet table */
for (i = 0; i < COCTET; i++) {
pixel = s->buf[stream_ptr++];
pixel = bytestream2_get_byte(&s->gb);
color_table_index = COCTET * color_octet_index + i;
s->color_octets[color_table_index] = pixel;
}
......@@ -353,7 +345,7 @@ static void smc_decode_stream(SmcContext *s)
if (color_octet_index == COLORS_PER_TABLE)
color_octet_index = 0;
} else
color_table_index = COCTET * s->buf[stream_ptr++];
color_table_index = COCTET * bytestream2_get_byte(&s->gb);
while (n_blocks--) {
/*
......@@ -363,15 +355,12 @@ static void smc_decode_stream(SmcContext *s)
flags_a = xx012456, flags_b = xx89A37B
*/
/* build the color flags */
color_flags_a =
((AV_RB16(s->buf + stream_ptr ) & 0xFFF0) << 8) |
(AV_RB16(s->buf + stream_ptr + 2) >> 4);
color_flags_b =
((AV_RB16(s->buf + stream_ptr + 4) & 0xFFF0) << 8) |
((s->buf[stream_ptr + 1] & 0x0F) << 8) |
((s->buf[stream_ptr + 3] & 0x0F) << 4) |
(s->buf[stream_ptr + 5] & 0x0F);
stream_ptr += 6;
int val1 = bytestream2_get_be16(&s->gb);
int val2 = bytestream2_get_be16(&s->gb);
int val3 = bytestream2_get_be16(&s->gb);
color_flags_a = ((val1 & 0xFFF0) << 8) | (val2 >> 4);
color_flags_b = ((val3 & 0xFFF0) << 8) |
((val1 & 0x0F) << 8) | ((val2 & 0x0F) << 4) | (val3 & 0x0F);
color_flags = color_flags_a;
/* flag mask actually acts as a bit shift count here */
......@@ -403,7 +392,7 @@ static void smc_decode_stream(SmcContext *s)
block_ptr = row_ptr + pixel_ptr;
for (pixel_y = 0; pixel_y < 4; pixel_y++) {
for (pixel_x = 0; pixel_x < 4; pixel_x++) {
pixels[block_ptr++] = s->buf[stream_ptr++];
pixels[block_ptr++] = bytestream2_get_byte(&s->gb);
}
block_ptr += row_inc;
}
......@@ -412,10 +401,12 @@ static void smc_decode_stream(SmcContext *s)
break;
case 0xF0:
av_log(s->avctx, AV_LOG_INFO, "0xF0 opcode seen in SMC chunk (contact the developers)\n");
av_log_missing_feature(s->avctx, "0xF0 opcode", 1);
break;
}
}
return;
}
static av_cold int smc_decode_init(AVCodecContext *avctx)
......@@ -439,8 +430,7 @@ static int smc_decode_frame(AVCodecContext *avctx,
SmcContext *s = avctx->priv_data;
const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
s->buf = buf;
s->size = buf_size;
bytestream2_init(&s->gb, buf, buf_size);
s->frame.reference = 1;
s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE |
......
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