* Flash Screen Video encoder
* @author Alex Beregszaszi
* @author Benjamin Larsson
+ *
+ * A description of the bitstream format for Flash Screen Video version 1/2
+ * is part of the SWF File Format Specification (version 10), which can be
+ * downloaded from http://www.adobe.com/devnet/swf.html.
*/
-/* Bitstream description
- * The picture is divided into blocks that are zlib-compressed.
- *
- * The decoder is fed complete frames, the frameheader contains:
- * 4 bits of block width
- * 12 bits of frame width
- * 4 bits of block height
- * 12 bits of frame height
- *
- * Directly after the header are the compressed blocks. The blocks
- * have their compressed size represented with 16 bits in the beginning.
- * If the size = 0 then the block is unchanged from the previous frame.
- * All blocks are decompressed until the buffer is consumed.
- *
+/*
* Encoding ideas: A basic encoder would just use a fixed block size.
* Block sizes can be multiples of 16, from 16 to 256. The blocks don't
* have to be quadratic. A brute force search with a set of different
#include <zlib.h>
#include "avcodec.h"
+#include "internal.h"
#include "put_bits.h"
#include "bytestream.h"
typedef struct FlashSVContext {
AVCodecContext *avctx;
uint8_t *previous_frame;
- AVFrame frame;
int image_width, image_height;
int block_width, block_height;
uint8_t *tmpblock;
return 0;
}
+static av_cold int flashsv_encode_end(AVCodecContext *avctx)
+{
+ FlashSVContext *s = avctx->priv_data;
+
+ deflateEnd(&s->zstream);
+
+ av_free(s->encbuffer);
+ av_free(s->previous_frame);
+ av_free(s->tmpblock);
+
+ av_frame_free(&avctx->coded_frame);
+
+ return 0;
+}
+
static av_cold int flashsv_encode_init(AVCodecContext *avctx)
{
FlashSVContext *s = avctx->priv_data;
return AVERROR(ENOMEM);
}
+ avctx->coded_frame = av_frame_alloc();
+ if (!avctx->coded_frame) {
+ flashsv_encode_end(avctx);
+ return AVERROR(ENOMEM);
+ }
+
return 0;
}
-static int encode_bitstream(FlashSVContext *s, AVFrame *p, uint8_t *buf,
+static int encode_bitstream(FlashSVContext *s, const AVFrame *p, uint8_t *buf,
int buf_size, int block_width, int block_height,
uint8_t *previous_frame, int *I_frame)
{
/* loop over all block columns */
for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
- int hp = j * block_height; // horizontal position in frame
- int hs = (j < v_blocks) ? block_height : v_part; // size of block
+ int y_pos = j * block_height; // vertical position in frame
+ int cur_blk_height = (j < v_blocks) ? block_height : v_part;
/* loop over all block rows */
for (i = 0; i < h_blocks + (h_part ? 1 : 0); i++) {
- int wp = i * block_width; // vertical position in frame
- int ws = (i < h_blocks) ? block_width : h_part; // size of block
+ int x_pos = i * block_width; // horizontal position in frame
+ int cur_blk_width = (i < h_blocks) ? block_width : h_part;
int ret = Z_OK;
uint8_t *ptr = buf + buf_pos;
/* copy the block to the temp buffer before compression
* (if it differs from the previous frame's block) */
res = copy_region_enc(p->data[0], s->tmpblock,
- s->image_height - (hp + hs + 1),
- wp, hs, ws, p->linesize[0], previous_frame);
+ s->image_height - (y_pos + cur_blk_height + 1),
+ x_pos, cur_blk_height, cur_blk_width,
+ p->linesize[0], previous_frame);
if (res || *I_frame) {
unsigned long zsize = 3 * block_width * block_height;
- ret = compress2(ptr + 2, &zsize, s->tmpblock, 3 * ws * hs, 9);
+ ret = compress2(ptr + 2, &zsize, s->tmpblock,
+ 3 * cur_blk_width * cur_blk_height, 9);
//ret = deflateReset(&s->zstream);
if (ret != Z_OK)
av_log(s->avctx, AV_LOG_ERROR,
"error while compressing block %dx%d\n", i, j);
- bytestream_put_be16(&ptr, (unsigned int) zsize);
+ bytestream_put_be16(&ptr, zsize);
buf_pos += zsize + 2;
- av_dlog(avctx, "buf_pos = %d\n", buf_pos);
+ av_dlog(s->avctx, "buf_pos = %d\n", buf_pos);
} else {
pred_blocks++;
bytestream_put_be16(&ptr, 0);
}
-static int flashsv_encode_frame(AVCodecContext *avctx, uint8_t *buf,
- int buf_size, void *data)
+static int flashsv_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
+ const AVFrame *pict, int *got_packet)
{
FlashSVContext * const s = avctx->priv_data;
- AVFrame *pict = data;
- AVFrame * const p = &s->frame;
+ const AVFrame * const p = pict;
uint8_t *pfptr;
int res;
int I_frame = 0;
int opt_w = 4, opt_h = 4;
- *p = *pict;
-
/* First frame needs to be a keyframe */
if (avctx->frame_number == 0) {
s->previous_frame = av_mallocz(FFABS(p->linesize[0]) * s->image_height);
I_frame = 1;
}
- if (buf_size < s->image_width * s->image_height * 3) {
+ if ((res = ff_alloc_packet(pkt, s->image_width * s->image_height * 3)) < 0) {
//Conservative upper bound check for compressed data
- av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n",
- buf_size, s->image_width * s->image_height * 3);
- return -1;
+ av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n",
+ s->image_width * s->image_height * 3);
+ return res;
}
- res = encode_bitstream(s, p, buf, buf_size, opt_w * 16, opt_h * 16,
- pfptr, &I_frame);
+ pkt->size = encode_bitstream(s, p, pkt->data, pkt->size, opt_w * 16, opt_h * 16,
+ pfptr, &I_frame);
//save the current frame
if (p->linesize[0] > 0)
//mark the frame type so the muxer can mux it correctly
if (I_frame) {
- p->pict_type = AV_PICTURE_TYPE_I;
- p->key_frame = 1;
+ avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
+ avctx->coded_frame->key_frame = 1;
s->last_key_frame = avctx->frame_number;
av_dlog(avctx, "Inserting keyframe at frame %d\n", avctx->frame_number);
} else {
- p->pict_type = AV_PICTURE_TYPE_P;
- p->key_frame = 0;
+ avctx->coded_frame->pict_type = AV_PICTURE_TYPE_P;
+ avctx->coded_frame->key_frame = 0;
}
- avctx->coded_frame = p;
-
- return res;
-}
-
-static av_cold int flashsv_encode_end(AVCodecContext *avctx)
-{
- FlashSVContext *s = avctx->priv_data;
-
- deflateEnd(&s->zstream);
-
- av_free(s->encbuffer);
- av_free(s->previous_frame);
- av_free(s->tmpblock);
+ if (avctx->coded_frame->key_frame)
+ pkt->flags |= AV_PKT_FLAG_KEY;
+ *got_packet = 1;
return 0;
}
AVCodec ff_flashsv_encoder = {
.name = "flashsv",
+ .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video"),
.type = AVMEDIA_TYPE_VIDEO,
- .id = CODEC_ID_FLASHSV,
+ .id = AV_CODEC_ID_FLASHSV,
.priv_data_size = sizeof(FlashSVContext),
.init = flashsv_encode_init,
- .encode = flashsv_encode_frame,
+ .encode2 = flashsv_encode_frame,
.close = flashsv_encode_end,
- .pix_fmts = (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_NONE},
- .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video"),
+ .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
};
-
projects / ffmpeg / blobdiff