[FFmpeg-devel] [PATCH 3/4] apng: Add a basic APNG encoder
Donny Yang
work at kota.moe
Tue Mar 31 14:37:24 CEST 2015
Signed-off-by: Donny Yang <work at kota.moe>
---
configure | 1 +
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 2 +-
libavcodec/pngenc.c | 151 +++++++++++++++++++++++++++++++++++++++++++++----
4 files changed, 144 insertions(+), 11 deletions(-)
diff --git a/configure b/configure
index 392946a..bc59271 100755
--- a/configure
+++ b/configure
@@ -2099,6 +2099,7 @@ amv_decoder_select="sp5x_decoder exif"
amv_encoder_select="aandcttables jpegtables mpegvideoenc"
ape_decoder_select="bswapdsp llauddsp"
apng_decoder_select="zlib"
+apng_encoder_select="huffyuvencdsp zlib"
asv1_decoder_select="blockdsp bswapdsp idctdsp"
asv1_encoder_select="bswapdsp fdctdsp pixblockdsp"
asv2_decoder_select="blockdsp bswapdsp idctdsp"
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index f8e2732..dd1d850 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -145,6 +145,7 @@ OBJS-$(CONFIG_ANM_DECODER) += anm.o
OBJS-$(CONFIG_ANSI_DECODER) += ansi.o cga_data.o
OBJS-$(CONFIG_APE_DECODER) += apedec.o
OBJS-$(CONFIG_APNG_DECODER) += png.o pngdec.o pngdsp.o
+OBJS-$(CONFIG_APNG_ENCODER) += png.o pngenc.o
OBJS-$(CONFIG_SSA_DECODER) += assdec.o ass.o ass_split.o
OBJS-$(CONFIG_SSA_ENCODER) += assenc.o ass.o
OBJS-$(CONFIG_ASS_DECODER) += assdec.o ass.o ass_split.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index 89acac1..ef3558a 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -108,7 +108,7 @@ void avcodec_register_all(void)
REGISTER_ENCDEC (AMV, amv);
REGISTER_DECODER(ANM, anm);
REGISTER_DECODER(ANSI, ansi);
- REGISTER_DECODER(APNG, apng);
+ REGISTER_ENCDEC (APNG, apng);
REGISTER_ENCDEC (ASV1, asv1);
REGISTER_ENCDEC (ASV2, asv2);
REGISTER_DECODER(AURA, aura);
diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c
index e7c343b..21e35f2 100644
--- a/libavcodec/pngenc.c
+++ b/libavcodec/pngenc.c
@@ -24,6 +24,7 @@
#include "bytestream.h"
#include "huffyuvencdsp.h"
#include "png.h"
+#include "apng.h"
#include "libavutil/avassert.h"
#include "libavutil/libm.h"
@@ -53,6 +54,10 @@ typedef struct PNGEncContext {
int bit_depth;
int color_type;
int bits_per_pixel;
+
+ // APNG
+ uint32_t palette_checksum; // Used to ensure a single unique palette
+ uint32_t sequence_number;
} PNGEncContext;
static void png_get_interlaced_row(uint8_t *dst, int row_size,
@@ -216,9 +221,34 @@ static void png_write_chunk(uint8_t **f, uint32_t tag,
bytestream_put_be32(f, crc);
}
+static void png_write_image_data(AVCodecContext *avctx,
+ const uint8_t *buf, int length)
+{
+ PNGEncContext *s = avctx->priv_data;
+ uint32_t crc = crc32(0, Z_NULL, 0);
+
+ if (avctx->codec_id == AV_CODEC_ID_PNG || avctx->frame_number == 0)
+ return png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), buf, length);
+
+ bytestream_put_be32(&s->bytestream, length + 4);
+
+ bytestream_put_be32(&s->bytestream, MKBETAG('f', 'd', 'A', 'T'));
+ bytestream_put_be32(&s->bytestream, s->sequence_number);
+ crc = crc32(crc, s->bytestream - 8, 8);
+
+ crc = crc32(crc, buf, length);
+ memcpy(s->bytestream, buf, length);
+ s->bytestream += length;
+
+ bytestream_put_be32(&s->bytestream, crc);
+
+ ++s->sequence_number;
+}
+
/* XXX: do filtering */
-static int png_write_row(PNGEncContext *s, const uint8_t *data, int size)
+static int png_write_row(AVCodecContext *avctx, const uint8_t *data, int size)
{
+ PNGEncContext *s = avctx->priv_data;
int ret;
s->zstream.avail_in = size;
@@ -229,8 +259,7 @@ static int png_write_row(PNGEncContext *s, const uint8_t *data, int size)
return -1;
if (s->zstream.avail_out == 0) {
if (s->bytestream_end - s->bytestream > IOBUF_SIZE + 100)
- png_write_chunk(&s->bytestream,
- MKTAG('I', 'D', 'A', 'T'), s->buf, IOBUF_SIZE);
+ png_write_image_data(avctx, s->buf, IOBUF_SIZE);
s->zstream.avail_out = IOBUF_SIZE;
s->zstream.next_out = s->buf;
}
@@ -409,7 +438,7 @@ static int encode_frame(AVCodecContext *avctx, const AVFrame *pict)
ptr, avctx->width);
crow = png_choose_filter(s, crow_buf, progressive_buf,
top, pass_row_size, s->bits_per_pixel >> 3);
- png_write_row(s, crow, pass_row_size + 1);
+ png_write_row(avctx, crow, pass_row_size + 1);
top = progressive_buf;
}
}
@@ -420,7 +449,7 @@ static int encode_frame(AVCodecContext *avctx, const AVFrame *pict)
ptr = p->data[0] + y * p->linesize[0];
crow = png_choose_filter(s, crow_buf, ptr, top,
row_size, s->bits_per_pixel >> 3);
- png_write_row(s, crow, row_size + 1);
+ png_write_row(avctx, crow, row_size + 1);
top = ptr;
}
}
@@ -430,7 +459,7 @@ static int encode_frame(AVCodecContext *avctx, const AVFrame *pict)
if (ret == Z_OK || ret == Z_STREAM_END) {
len = IOBUF_SIZE - s->zstream.avail_out;
if (len > 0 && s->bytestream_end - s->bytestream > len + 100) {
- png_write_chunk(&s->bytestream, MKTAG('I', 'D', 'A', 'T'), s->buf, len);
+ png_write_image_data(avctx, s->buf, len);
}
s->zstream.avail_out = IOBUF_SIZE;
s->zstream.next_out = s->buf;
@@ -452,15 +481,15 @@ the_end:
return ret;
}
-static int encode(AVCodecContext *avctx, AVPacket *pkt,
- const AVFrame *pict, int *got_packet)
+static int encode_png(AVCodecContext *avctx, AVPacket *pkt,
+ const AVFrame *pict, int *got_packet)
{
PNGEncContext *s = avctx->priv_data;
int ret;
int enc_row_size;
size_t max_packet_size;
- enc_row_size = deflateBound(&s->zstream, row_size);
+ enc_row_size = deflateBound(&s->zstream, (avctx->width * s->bits_per_pixel + 7) >> 3);
max_packet_size =
FF_MIN_BUFFER_SIZE + // headers
avctx->height * (
@@ -497,6 +526,81 @@ static int encode(AVCodecContext *avctx, AVPacket *pkt,
return 0;
}
+static int encode_apng(AVCodecContext *avctx, AVPacket *pkt,
+ const AVFrame *pict, int *got_packet)
+{
+ PNGEncContext *s = avctx->priv_data;
+ int ret;
+ int enc_row_size;
+ size_t max_packet_size;
+ uint8_t buf[26];
+
+ if (avctx->codec_id == AV_CODEC_ID_APNG && s->color_type == PNG_COLOR_TYPE_PALETTE) {
+ uint32_t checksum = crc32(crc32(0, Z_NULL, 0), pict->data[1], 256 * sizeof(uint32_t));
+
+ if (avctx->frame_number == 0) {
+ s->palette_checksum = checksum;
+ } else if (checksum != s->palette_checksum) {
+ av_log(avctx, AV_LOG_ERROR,
+ "Input contains more than one unique palette. APNG does not support multiple palettes.\n");
+ return -1;
+ }
+ }
+
+ enc_row_size = deflateBound(&s->zstream, (avctx->width * s->bits_per_pixel + 7) >> 3);
+ max_packet_size =
+ FF_MIN_BUFFER_SIZE + // headers
+ avctx->height * (
+ enc_row_size +
+ (4 + 12) * (((int64_t)enc_row_size + IOBUF_SIZE - 1) / IOBUF_SIZE) // fdAT * ceil(enc_row_size / IOBUF_SIZE)
+ );
+ if (max_packet_size > INT_MAX)
+ return AVERROR(ENOMEM);
+ ret = ff_alloc_packet2(avctx, pkt, max_packet_size);
+ if (ret)
+ return ret;
+
+ s->bytestream_start =
+ s->bytestream = pkt->data;
+ s->bytestream_end = pkt->data + pkt->size;
+
+ if (avctx->frame_number == 0) {
+ ret = encode_headers(avctx, pict);
+ if (ret)
+ return ret;
+
+ avctx->extradata = av_malloc(s->bytestream - s->bytestream_start);
+ if (!avctx->extradata)
+ return AVERROR(ENOMEM);
+ avctx->extradata_size = s->bytestream - s->bytestream_start;
+ memcpy(avctx->extradata, s->bytestream_start, s->bytestream - s->bytestream_start);
+
+ s->bytestream = s->bytestream_start;
+ }
+
+ AV_WB32(buf, s->sequence_number);
+ AV_WB32(buf + 4, avctx->width);
+ AV_WB32(buf + 8, avctx->height);
+ AV_WB32(buf + 12, 0); // x offset
+ AV_WB32(buf + 16, 0); // y offset
+ AV_WB16(buf + 20, 0); // delay numerator (filled in during muxing)
+ AV_WB16(buf + 22, 0); // delay denominator
+ buf[24] = APNG_DISPOSE_OP_BACKGROUND;
+ buf[25] = APNG_BLEND_OP_SOURCE;
+ png_write_chunk(&s->bytestream, MKTAG('f', 'c', 'T', 'L'), buf, 26);
+ ++s->sequence_number;
+
+ ret = encode_frame(avctx, pict);
+ if (ret)
+ return ret;
+
+ pkt->size = s->bytestream - s->bytestream_start;
+ pkt->flags |= AV_PKT_FLAG_KEY;
+ *got_packet = 1;
+
+ return 0;
+}
+
static av_cold int png_enc_init(AVCodecContext *avctx)
{
PNGEncContext *s = avctx->priv_data;
@@ -624,6 +728,13 @@ static const AVClass pngenc_class = {
.version = LIBAVUTIL_VERSION_INT,
};
+static const AVClass apngenc_class = {
+ .class_name = "APNG encoder",
+ .item_name = av_default_item_name,
+ .option = options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
AVCodec ff_png_encoder = {
.name = "png",
.long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
@@ -632,7 +743,7 @@ AVCodec ff_png_encoder = {
.priv_data_size = sizeof(PNGEncContext),
.init = png_enc_init,
.close = png_enc_close,
- .encode2 = encode,
+ .encode2 = encode_png,
.capabilities = CODEC_CAP_FRAME_THREADS | CODEC_CAP_INTRA_ONLY,
.pix_fmts = (const enum AVPixelFormat[]) {
AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA,
@@ -644,3 +755,23 @@ AVCodec ff_png_encoder = {
},
.priv_class = &pngenc_class,
};
+
+AVCodec ff_apng_encoder = {
+ .name = "apng",
+ .long_name = NULL_IF_CONFIG_SMALL("APNG (Animated Portable Network Graphics) image"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .id = AV_CODEC_ID_APNG,
+ .priv_data_size = sizeof(PNGEncContext),
+ .init = png_enc_init,
+ .close = png_enc_close,
+ .encode2 = encode_apng,
+ .pix_fmts = (const enum AVPixelFormat[]) {
+ AV_PIX_FMT_RGB24, AV_PIX_FMT_RGBA,
+ AV_PIX_FMT_RGB48BE, AV_PIX_FMT_RGBA64BE,
+ AV_PIX_FMT_PAL8,
+ AV_PIX_FMT_GRAY8, AV_PIX_FMT_GRAY8A,
+ AV_PIX_FMT_GRAY16BE, AV_PIX_FMT_YA16BE,
+ AV_PIX_FMT_MONOBLACK, AV_PIX_FMT_NONE
+ },
+ .priv_class = &apngenc_class,
+};
--
2.3.4
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