[FFmpeg-devel] [PATCH 3/7] avcodec/sgidec: Avoid redundant private context
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Fri Sep 30 20:05:11 EEST 2022
SGI is intra-frame only; the decoder therefore does not
maintain any state between frames, so remove
the private context.
Also rename depth to nb_components.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
libavcodec/sgidec.c | 158 ++++++++++++++++++++------------------------
1 file changed, 73 insertions(+), 85 deletions(-)
diff --git a/libavcodec/sgidec.c b/libavcodec/sgidec.c
index a449859bf8..bd49a3510d 100644
--- a/libavcodec/sgidec.c
+++ b/libavcodec/sgidec.c
@@ -25,25 +25,17 @@
#include "decode.h"
#include "sgi.h"
-typedef struct SgiState {
- AVCodecContext *avctx;
- unsigned int width;
- int height;
- unsigned int depth;
- unsigned int bytes_per_channel;
- int linesize;
- GetByteContext g;
-} SgiState;
-
/**
* Expand an RLE row into a channel.
- * @param s the current image state
+ * @param logctx a logcontext
* @param out_buf Points to one line after the output buffer.
+ * @param g GetByteContext used to read input from
* @param len length of out_buf in bytes
* @param pixelstride pixel stride of input buffer
* @return size of output in bytes, else return error code.
*/
-static int expand_rle_row8(SgiState *s, uint8_t *out_buf,
+static int expand_rle_row8(void *logctx, uint8_t *out_buf,
+ GetByteContext *g,
int len, int pixelstride)
{
unsigned char pixel, count;
@@ -51,26 +43,26 @@ static int expand_rle_row8(SgiState *s, uint8_t *out_buf,
uint8_t *out_end = out_buf + len;
while (out_buf < out_end) {
- if (bytestream2_get_bytes_left(&s->g) < 1)
+ if (bytestream2_get_bytes_left(g) < 1)
return AVERROR_INVALIDDATA;
- pixel = bytestream2_get_byteu(&s->g);
+ pixel = bytestream2_get_byteu(g);
if (!(count = (pixel & 0x7f))) {
break;
}
/* Check for buffer overflow. */
if (out_end - out_buf <= pixelstride * (count - 1)) {
- av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
+ av_log(logctx, AV_LOG_ERROR, "Invalid pixel count.\n");
return AVERROR_INVALIDDATA;
}
if (pixel & 0x80) {
while (count--) {
- *out_buf = bytestream2_get_byte(&s->g);
+ *out_buf = bytestream2_get_byte(g);
out_buf += pixelstride;
}
} else {
- pixel = bytestream2_get_byte(&s->g);
+ pixel = bytestream2_get_byte(g);
while (count--) {
*out_buf = pixel;
@@ -81,7 +73,8 @@ static int expand_rle_row8(SgiState *s, uint8_t *out_buf,
return (out_buf - orig) / pixelstride;
}
-static int expand_rle_row16(SgiState *s, uint16_t *out_buf,
+static int expand_rle_row16(void *logctx, uint16_t *out_buf,
+ GetByteContext *g,
int len, int pixelstride)
{
unsigned short pixel;
@@ -90,26 +83,26 @@ static int expand_rle_row16(SgiState *s, uint16_t *out_buf,
uint16_t *out_end = out_buf + len;
while (out_buf < out_end) {
- if (bytestream2_get_bytes_left(&s->g) < 2)
+ if (bytestream2_get_bytes_left(g) < 2)
return AVERROR_INVALIDDATA;
- pixel = bytestream2_get_be16u(&s->g);
+ pixel = bytestream2_get_be16u(g);
if (!(count = (pixel & 0x7f)))
break;
/* Check for buffer overflow. */
if (out_end - out_buf <= pixelstride * (count - 1)) {
- av_log(s->avctx, AV_LOG_ERROR, "Invalid pixel count.\n");
+ av_log(logctx, AV_LOG_ERROR, "Invalid pixel count.\n");
return AVERROR_INVALIDDATA;
}
if (pixel & 0x80) {
while (count--) {
- pixel = bytestream2_get_ne16(&s->g);
+ pixel = bytestream2_get_ne16(g);
AV_WN16A(out_buf, pixel);
out_buf += pixelstride;
}
} else {
- pixel = bytestream2_get_ne16(&s->g);
+ pixel = bytestream2_get_ne16(g);
while (count--) {
AV_WN16A(out_buf, pixel);
@@ -127,34 +120,38 @@ static int expand_rle_row16(SgiState *s, uint16_t *out_buf,
* @param s the current image state
* @return 0 if no error, else return error code.
*/
-static int read_rle_sgi(uint8_t *last_line, SgiState *s)
+static int read_rle_sgi(void *logctx, uint8_t *last_line, GetByteContext *g,
+ ptrdiff_t stride, unsigned width, unsigned height,
+ unsigned nb_components, unsigned bytes_per_channel)
{
uint8_t *dest_row;
- unsigned int len = s->height * s->depth * 4;
- GetByteContext g_table = s->g;
+ unsigned int len = height * nb_components * 4;
+ GetByteContext g_table = *g;
unsigned int start_offset;
int linesize, ret;
/* size of RLE offset and length tables */
- if (len * 2 > bytestream2_get_bytes_left(&s->g)) {
+ if (len * 2 > bytestream2_get_bytes_left(g)) {
return AVERROR_INVALIDDATA;
}
- for (unsigned z = 0; z < s->depth; z++) {
+ for (unsigned z = 0; z < nb_components; z++) {
dest_row = last_line;
- for (int remaining_lines = s->height;;) {
- linesize = s->width * s->depth;
+ for (unsigned remaining_lines = height;;) {
+ linesize = width * nb_components;
start_offset = bytestream2_get_be32(&g_table);
- bytestream2_seek(&s->g, start_offset, SEEK_SET);
- if (s->bytes_per_channel == 1)
- ret = expand_rle_row8(s, dest_row + z, linesize, s->depth);
+ bytestream2_seek(g, start_offset, SEEK_SET);
+ if (bytes_per_channel == 1)
+ ret = expand_rle_row8(logctx, dest_row + z, g,
+ linesize, nb_components);
else
- ret = expand_rle_row16(s, (uint16_t *)dest_row + z, linesize, s->depth);
- if (ret != s->width)
+ ret = expand_rle_row16(logctx, (uint16_t *)dest_row + z, g,
+ linesize, nb_components);
+ if (ret != width)
return AVERROR_INVALIDDATA;
if (--remaining_lines == 0)
break;
- dest_row -= s->linesize;
+ dest_row -= stride;
}
}
return 0;
@@ -166,33 +163,34 @@ static int read_rle_sgi(uint8_t *last_line, SgiState *s)
* @param s the current image state
* @return 0 if read success, else return error code.
*/
-static int read_uncompressed_sgi(unsigned char *out_buf, SgiState *s)
+static int read_uncompressed_sgi(unsigned char *out_buf, GetByteContext *g,
+ ptrdiff_t stride, unsigned width, unsigned height,
+ unsigned nb_components, unsigned bytes_per_channel)
{
- int x, y, z;
- unsigned int offset = s->height * s->width * s->bytes_per_channel;
+ unsigned int offset = height * width * bytes_per_channel;
GetByteContext gp[4];
uint8_t *out_end;
/* Test buffer size. */
- if (offset * s->depth > bytestream2_get_bytes_left(&s->g))
+ if (offset * nb_components > bytestream2_get_bytes_left(g))
return AVERROR_INVALIDDATA;
/* Create a reader for each plane */
- for (z = 0; z < s->depth; z++) {
- gp[z] = s->g;
+ for (unsigned z = 0; z < nb_components; z++) {
+ gp[z] = *g;
bytestream2_skip(&gp[z], z * offset);
}
- for (y = s->height - 1; y >= 0; y--) {
- out_end = out_buf + (y * s->linesize);
- if (s->bytes_per_channel == 1) {
- for (x = s->width; x > 0; x--)
- for (z = 0; z < s->depth; z++)
+ for (int y = height - 1; y >= 0; y--) {
+ out_end = out_buf + y * stride;
+ if (bytes_per_channel == 1) {
+ for (unsigned x = width; x > 0; x--)
+ for (unsigned z = 0; z < nb_components; z++)
*out_end++ = bytestream2_get_byteu(&gp[z]);
} else {
uint16_t *out16 = (uint16_t *)out_end;
- for (x = s->width; x > 0; x--)
- for (z = 0; z < s->depth; z++)
+ for (unsigned x = width; x > 0; x--)
+ for (unsigned z = 0; z < nb_components; z++)
*out16++ = bytestream2_get_ne16u(&gp[z]);
}
}
@@ -202,31 +200,32 @@ static int read_uncompressed_sgi(unsigned char *out_buf, SgiState *s)
static int decode_frame(AVCodecContext *avctx, AVFrame *p,
int *got_frame, AVPacket *avpkt)
{
- SgiState *s = avctx->priv_data;
- unsigned int dimension, rle;
+ GetByteContext g;
+ unsigned int bytes_per_channel, nb_components, dimension, rle, width;
+ int height;
int ret = 0;
uint8_t *out_buf, *last_line;
- bytestream2_init(&s->g, avpkt->data, avpkt->size);
- if (bytestream2_get_bytes_left(&s->g) < SGI_HEADER_SIZE) {
+ bytestream2_init(&g, avpkt->data, avpkt->size);
+ if (bytestream2_get_bytes_left(&g) < SGI_HEADER_SIZE) {
av_log(avctx, AV_LOG_ERROR, "buf_size too small (%d)\n", avpkt->size);
return AVERROR_INVALIDDATA;
}
/* Test for SGI magic. */
- if (bytestream2_get_be16u(&s->g) != SGI_MAGIC) {
+ if (bytestream2_get_be16u(&g) != SGI_MAGIC) {
av_log(avctx, AV_LOG_ERROR, "bad magic number\n");
return AVERROR_INVALIDDATA;
}
- rle = bytestream2_get_byteu(&s->g);
- s->bytes_per_channel = bytestream2_get_byteu(&s->g);
- dimension = bytestream2_get_be16u(&s->g);
- s->width = bytestream2_get_be16u(&s->g);
- s->height = bytestream2_get_be16u(&s->g);
- s->depth = bytestream2_get_be16u(&s->g);
+ rle = bytestream2_get_byteu(&g);
+ bytes_per_channel = bytestream2_get_byteu(&g);
+ dimension = bytestream2_get_be16u(&g);
+ width = bytestream2_get_be16u(&g);
+ height = bytestream2_get_be16u(&g);
+ nb_components = bytestream2_get_be16u(&g);
- if (s->bytes_per_channel != 1 && s->bytes_per_channel != 2) {
+ if (bytes_per_channel != 1 && bytes_per_channel != 2) {
av_log(avctx, AV_LOG_ERROR, "wrong channel number\n");
return AVERROR_INVALIDDATA;
}
@@ -237,18 +236,18 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *p,
return AVERROR_INVALIDDATA;
}
- if (s->depth == SGI_GRAYSCALE) {
- avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
- } else if (s->depth == SGI_RGB) {
- avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
- } else if (s->depth == SGI_RGBA) {
- avctx->pix_fmt = s->bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA;
+ if (nb_components == SGI_GRAYSCALE) {
+ avctx->pix_fmt = bytes_per_channel == 2 ? AV_PIX_FMT_GRAY16BE : AV_PIX_FMT_GRAY8;
+ } else if (nb_components == SGI_RGB) {
+ avctx->pix_fmt = bytes_per_channel == 2 ? AV_PIX_FMT_RGB48BE : AV_PIX_FMT_RGB24;
+ } else if (nb_components == SGI_RGBA) {
+ avctx->pix_fmt = bytes_per_channel == 2 ? AV_PIX_FMT_RGBA64BE : AV_PIX_FMT_RGBA;
} else {
av_log(avctx, AV_LOG_ERROR, "wrong picture format\n");
return AVERROR_INVALIDDATA;
}
- ret = ff_set_dimensions(avctx, s->width, s->height);
+ ret = ff_set_dimensions(avctx, width, height);
if (ret < 0)
return ret;
@@ -259,16 +258,16 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *p,
p->key_frame = 1;
out_buf = p->data[0];
- last_line = out_buf + p->linesize[0] * (s->height - 1);
-
- s->linesize = p->linesize[0];
+ last_line = out_buf + p->linesize[0] * (height - 1);
/* Skip header. */
- bytestream2_seek(&s->g, SGI_HEADER_SIZE, SEEK_SET);
+ bytestream2_seek(&g, SGI_HEADER_SIZE, SEEK_SET);
if (rle) {
- ret = read_rle_sgi(last_line, s);
+ ret = read_rle_sgi(avctx, last_line, &g, p->linesize[0],
+ width, height, nb_components, bytes_per_channel);
} else {
- ret = read_uncompressed_sgi(out_buf, s);
+ ret = read_uncompressed_sgi(out_buf, &g, p->linesize[0],
+ width, height, nb_components, bytes_per_channel);
}
if (ret)
return ret;
@@ -277,22 +276,11 @@ static int decode_frame(AVCodecContext *avctx, AVFrame *p,
return avpkt->size;
}
-static av_cold int sgi_decode_init(AVCodecContext *avctx)
-{
- SgiState *s = avctx->priv_data;
-
- s->avctx = avctx;
-
- return 0;
-}
-
const FFCodec ff_sgi_decoder = {
.p.name = "sgi",
CODEC_LONG_NAME("SGI image"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_SGI,
- .priv_data_size = sizeof(SgiState),
FF_CODEC_DECODE_CB(decode_frame),
- .init = sgi_decode_init,
.p.capabilities = AV_CODEC_CAP_DR1,
};
--
2.34.1
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