[FFmpeg-devel] [PATCH 1/4] libavcodec/pngdec: support 'previous' dispose operation for APNG.
Benoit Fouet
benoit.fouet at free.fr
Wed Dec 3 14:16:55 CET 2014
---
libavcodec/pngdec.c | 72 +++++++++++++++++++++++++++++++++++++----------------
1 file changed, 50 insertions(+), 22 deletions(-)
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 229a6d6..b1e77e5 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -38,6 +38,7 @@ typedef struct PNGDecContext {
AVCodecContext *avctx;
GetByteContext gb;
+ ThreadFrame previous_picture;
ThreadFrame last_picture;
ThreadFrame picture;
@@ -55,6 +56,7 @@ typedef struct PNGDecContext {
int bits_per_pixel;
int bpp;
+ int frame_id;
uint8_t *image_buf;
int image_linesize;
uint32_t palette[256];
@@ -827,13 +829,14 @@ static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s,
return AVERROR_INVALIDDATA;
/* always (re)start with a clean frame */
- if (sequence_number == 0)
+ if (sequence_number == 0) {
s->dispose_op = APNG_DISPOSE_OP_BACKGROUND;
-
- if (s->dispose_op == APNG_DISPOSE_OP_PREVIOUS) {
- av_log(avctx, AV_LOG_ERROR,
- "Dispose operation 'previous' is not yet implemented, using 'none'.\n");
- s->dispose_op = APNG_DISPOSE_OP_NONE;
+ s->frame_id = 0;
+ } else {
+ s->frame_id++;
+ if (s->frame_id == 1 && s->dispose_op == APNG_DISPOSE_OP_PREVIOUS)
+ /* previous for the second frame is the first frame */
+ s->dispose_op = APNG_DISPOSE_OP_NONE;
}
return 0;
@@ -864,8 +867,9 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
{
int i, j;
uint8_t *pd = p->data[0];
- /* TODO make pd_last point to the one before for APNG_DISPOSE_OP_PREVIOUS */
uint8_t *pd_last = s->last_picture.f->data[0];
+ uint8_t *pd_last_region = s->dispose_op == APNG_DISPOSE_OP_PREVIOUS ?
+ s->previous_picture.f->data[0] : s->last_picture.f->data[0];
int ls = FFMIN(av_image_get_linesize(p->format, s->width, 0), s->width * s->bpp);
if (s->blend_op == APNG_BLEND_OP_OVER &&
@@ -876,6 +880,9 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
}
ff_thread_await_progress(&s->last_picture, INT_MAX, 0);
+ if (s->dispose_op == APNG_DISPOSE_OP_PREVIOUS)
+ ff_thread_await_progress(&s->previous_picture, INT_MAX, 0);
+
for (j = 0; j < s->y_offset; j++) {
for (i = 0; i < ls; i++)
pd[i] = pd_last[i];
@@ -886,6 +893,7 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
if (s->dispose_op != APNG_DISPOSE_OP_BACKGROUND && s->blend_op == APNG_BLEND_OP_OVER) {
uint8_t ri, gi, bi, ai;
+ pd_last_region += s->y_offset * s->image_linesize;
if (avctx->pix_fmt == AV_PIX_FMT_RGBA) {
ri = 0;
gi = 1;
@@ -907,17 +915,17 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
/* output = alpha * foreground + (1-alpha) * background */
switch (alpha) {
case 0:
- pd[i+ri] = pd_last[i+ri];
- pd[i+gi] = pd_last[i+gi];
- pd[i+bi] = pd_last[i+bi];
+ pd[i+ri] = pd_last_region[i+ri];
+ pd[i+gi] = pd_last_region[i+gi];
+ pd[i+bi] = pd_last_region[i+bi];
pd[i+ai] = 0xff;
break;
case 255:
break;
default:
- pd[i+ri] = FAST_DIV255(alpha * pd[i+ri] + (255 - alpha) * pd_last[i+ri]);
- pd[i+gi] = FAST_DIV255(alpha * pd[i+gi] + (255 - alpha) * pd_last[i+gi]);
- pd[i+bi] = FAST_DIV255(alpha * pd[i+bi] + (255 - alpha) * pd_last[i+bi]);
+ pd[i+ri] = FAST_DIV255(alpha * pd[i+ri] + (255 - alpha) * pd_last_region[i+ri]);
+ pd[i+gi] = FAST_DIV255(alpha * pd[i+gi] + (255 - alpha) * pd_last_region[i+gi]);
+ pd[i+bi] = FAST_DIV255(alpha * pd[i+bi] + (255 - alpha) * pd_last_region[i+bi]);
pd[i+ai] = 0xff;
break;
}
@@ -926,6 +934,7 @@ static int handle_p_frame_apng(AVCodecContext *avctx, PNGDecContext *s,
pd[i] = pd_last[i];
pd += s->image_linesize;
pd_last += s->image_linesize;
+ pd_last_region += s->image_linesize;
}
} else {
for (j = s->y_offset; j < s->y_offset + s->cur_h; j++) {
@@ -955,6 +964,7 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
uint32_t tag, length;
int decode_next_dat = 0;
int ret = AVERROR_INVALIDDATA;
+ AVFrame *ref;
for (;;) {
length = bytestream2_get_bytes_left(&s->gb);
@@ -1053,11 +1063,13 @@ exit_loop:
handle_small_bpp(s, p);
/* handle p-frames only if a predecessor frame is available */
- if (s->last_picture.f->data[0]) {
+ ref = s->dispose_op == APNG_DISPOSE_OP_PREVIOUS ?
+ s->previous_picture.f : s->last_picture.f;
+ if (ref->data[0]) {
if ( !(avpkt->flags & AV_PKT_FLAG_KEY) && avctx->codec_tag != AV_RL32("MPNG")
- && s->last_picture.f->width == p->width
- && s->last_picture.f->height== p->height
- && s->last_picture.f->format== p->format
+ && ref->width == p->width
+ && ref->height== p->height
+ && ref->format== p->format
) {
if (CONFIG_PNG_DECODER && avctx->codec_id != AV_CODEC_ID_APNG)
handle_p_frame_png(s, p);
@@ -1141,9 +1153,13 @@ static int decode_frame_apng(AVCodecContext *avctx,
PNGDecContext *const s = avctx->priv_data;
int ret;
AVFrame *p;
+ ThreadFrame tmp;
- ff_thread_release_buffer(avctx, &s->last_picture);
- FFSWAP(ThreadFrame, s->picture, s->last_picture);
+ ff_thread_release_buffer(avctx, &s->previous_picture);
+ tmp = s->previous_picture;
+ s->previous_picture = s->last_picture;
+ s->last_picture = s->picture;
+ s->picture = tmp;
p = s->picture.f;
if (!(s->state & PNG_IHDR)) {
@@ -1193,13 +1209,22 @@ static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
{
PNGDecContext *psrc = src->priv_data;
PNGDecContext *pdst = dst->priv_data;
+ int ret;
if (dst == src)
return 0;
+ pdst->frame_id = psrc->frame_id;
+
ff_thread_release_buffer(dst, &pdst->picture);
- if (psrc->picture.f->data[0])
- return ff_thread_ref_frame(&pdst->picture, &psrc->picture);
+ if (psrc->picture.f->data[0] &&
+ (ret = ff_thread_ref_frame(&pdst->picture, &psrc->picture)) < 0)
+ return ret;
+ if (CONFIG_APNG_DECODER && dst->codec_id == AV_CODEC_ID_APNG) {
+ ff_thread_release_buffer(dst, &pdst->last_picture);
+ if (psrc->last_picture.f->data[0])
+ return ff_thread_ref_frame(&pdst->last_picture, &psrc->last_picture);
+ }
return 0;
}
@@ -1209,9 +1234,10 @@ static av_cold int png_dec_init(AVCodecContext *avctx)
PNGDecContext *s = avctx->priv_data;
s->avctx = avctx;
+ s->previous_picture.f = av_frame_alloc();
s->last_picture.f = av_frame_alloc();
s->picture.f = av_frame_alloc();
- if (!s->last_picture.f || !s->picture.f)
+ if (!s->previous_picture.f || !s->last_picture.f || !s->picture.f)
return AVERROR(ENOMEM);
if (!avctx->internal->is_copy) {
@@ -1226,6 +1252,8 @@ static av_cold int png_dec_end(AVCodecContext *avctx)
{
PNGDecContext *s = avctx->priv_data;
+ ff_thread_release_buffer(avctx, &s->previous_picture);
+ av_frame_free(&s->previous_picture.f);
ff_thread_release_buffer(avctx, &s->last_picture);
av_frame_free(&s->last_picture.f);
ff_thread_release_buffer(avctx, &s->picture);
--
2.2.0
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