[FFmpeg-devel] [PATCH 1/2] avcodec/pngdec: add APNG support.
Benoit Fouet
benoit.fouet at free.fr
Thu Nov 20 15:07:17 CET 2014
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/avcodec.h | 1 +
libavcodec/codec_desc.c | 8 +++
libavcodec/pngdec.c | 142 +++++++++++++++++++++++++++++++++++++++++++++++-
5 files changed, 150 insertions(+), 3 deletions(-)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 6c625ce..fa0f53d 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -136,6 +136,7 @@ OBJS-$(CONFIG_AMV_ENCODER) += mjpegenc.o mjpeg.o mjpegenc_common.o \
OBJS-$(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_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 d08abd8..0d39d33 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -105,6 +105,7 @@ void avcodec_register_all(void)
REGISTER_ENCDEC (AMV, amv);
REGISTER_DECODER(ANM, anm);
REGISTER_DECODER(ANSI, ansi);
+ REGISTER_DECODER(APNG, apng);
REGISTER_ENCDEC (ASV1, asv1);
REGISTER_ENCDEC (ASV2, asv2);
REGISTER_DECODER(AURA, aura);
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index eac3fc7..3323284 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -319,6 +319,7 @@ enum AVCodecID {
AV_CODEC_ID_HEVC = MKBETAG('H','2','6','5'),
#define AV_CODEC_ID_H265 AV_CODEC_ID_HEVC
AV_CODEC_ID_VP7 = MKBETAG('V','P','7','0'),
+ AV_CODEC_ID_APNG = MKBETAG('A','P','N','G'),
/* various PCM "codecs" */
AV_CODEC_ID_FIRST_AUDIO = 0x10000, ///< A dummy id pointing at the start of audio codecs
diff --git a/libavcodec/codec_desc.c b/libavcodec/codec_desc.c
index eeb4505..0af66f4 100644
--- a/libavcodec/codec_desc.c
+++ b/libavcodec/codec_desc.c
@@ -1440,6 +1440,14 @@ static const AVCodecDescriptor codec_descriptors[] = {
.props = AV_CODEC_PROP_INTRA_ONLY | AV_CODEC_PROP_LOSSLESS,
.mime_types= MT("image/x-xwindowdump"),
},
+ {
+ .id = AV_CODEC_ID_APNG,
+ .type = AVMEDIA_TYPE_VIDEO,
+ .name = "apng",
+ .long_name = NULL_IF_CONFIG_SMALL("APNG (Animated Portable Network Graphics) image"),
+ .props = AV_CODEC_PROP_LOSSLESS,
+ .mime_types= MT("image/png"),
+ },
/* various PCM "codecs" */
{
diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
index 57b73c1..2e7e627 100644
--- a/libavcodec/pngdec.c
+++ b/libavcodec/pngdec.c
@@ -786,15 +786,55 @@ static void handle_small_bpp(PNGDecContext *s, AVFrame *p)
}
}
+static int decode_fctl_chunk(AVCodecContext *avctx, PNGDecContext *s,
+ uint32_t length)
+{
+ uint32_t sequence_number, width, height, x_offset, y_offset;
+
+ if (length != 26)
+ return AVERROR_INVALIDDATA;
+
+ sequence_number = bytestream2_get_be32(&s->gb);
+ width = bytestream2_get_be32(&s->gb);
+ height = bytestream2_get_be32(&s->gb);
+ x_offset = bytestream2_get_be32(&s->gb);
+ y_offset = bytestream2_get_be32(&s->gb);
+ bytestream2_skip(&s->gb, 10); /* delay_num (2)
+ * delay_den (2)
+ * dispose_op (1)
+ * blend_op (1)
+ * crc (4)
+ */
+
+ if (width != s->width || height != s->height ||
+ x_offset != 0 || y_offset != 0) {
+ if (sequence_number == 0)
+ return AVERROR_INVALIDDATA;
+ avpriv_request_sample(avctx, "non key frames");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ return 0;
+}
+
static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
AVFrame *p, AVPacket *avpkt)
{
AVDictionary *metadata = NULL;
uint32_t tag, length;
+ int decode_next_dat = 0;
+ int ret = AVERROR_INVALIDDATA;
for (;;) {
- if (bytestream2_get_bytes_left(&s->gb) <= 0) {
- av_log(avctx, AV_LOG_ERROR, "%d bytes left\n", bytestream2_get_bytes_left(&s->gb));
+ length = bytestream2_get_bytes_left(&s->gb);
+ if (length <= 0) {
+ if (avctx->codec_id == AV_CODEC_ID_APNG && length == 0) {
+ if (!(s->state & PNG_IDAT))
+ return 0;
+ else
+ goto exit_loop;
+ }
+ av_log(avctx, AV_LOG_ERROR, "%d bytes left\n", length);
if ( s->state & PNG_ALLIMAGE
&& avctx->strict_std_compliance <= FF_COMPLIANCE_NORMAL)
goto exit_loop;
@@ -822,7 +862,27 @@ static int decode_frame_common(AVCodecContext *avctx, PNGDecContext *s,
if (decode_phys_chunk(avctx, s) < 0)
goto fail;
break;
+ case MKTAG('f', 'c', 'T', 'L'):
+ if (avctx->codec_id != AV_CODEC_ID_APNG)
+ goto skip_tag;
+ if ((ret = decode_fctl_chunk(avctx, s, length)) < 0)
+ goto fail;
+ decode_next_dat = 1;
+ break;
+ case MKTAG('f', 'd', 'A', 'T'):
+ if (avctx->codec_id != AV_CODEC_ID_APNG)
+ goto skip_tag;
+ if (!decode_next_dat)
+ goto fail;
+ bytestream2_get_be32(&s->gb);
+ length -= 4;
+ /* fallthrough */
case MKTAG('I', 'D', 'A', 'T'):
+ if (avctx->codec_id == AV_CODEC_ID_APNG) {
+ if (!decode_next_dat)
+ goto skip_tag;
+ decode_next_dat = 0;
+ }
if (decode_idat_chunk(avctx, s, length, p) < 0)
goto fail;
break;
@@ -894,9 +954,10 @@ exit_loop:
fail:
av_dict_free(&metadata);
ff_thread_report_progress(&s->picture, INT_MAX, 0);
- return AVERROR_INVALIDDATA;
+ return ret;
}
+#if CONFIG_PNG_DECODER
static int decode_frame_png(AVCodecContext *avctx,
void *data, int *got_frame,
AVPacket *avpkt)
@@ -948,6 +1009,63 @@ the_end:
s->crow_buf = NULL;
return ret;
}
+#endif
+
+#if CONFIG_APNG_DECODER
+static int decode_frame_apng(AVCodecContext *avctx,
+ void *data, int *got_frame,
+ AVPacket *avpkt)
+{
+ PNGDecContext *const s = avctx->priv_data;
+ int ret;
+ AVFrame *p;
+
+ ff_thread_release_buffer(avctx, &s->last_picture);
+ FFSWAP(ThreadFrame, s->picture, s->last_picture);
+ p = s->picture.f;
+
+ if (!(s->state & PNG_IHDR)) {
+ if (!avctx->extradata_size)
+ return AVERROR_INVALIDDATA;
+
+ /* only init fields, there is no zlib use in extradata */
+ s->zstream.zalloc = ff_png_zalloc;
+ s->zstream.zfree = ff_png_zfree;
+
+ bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
+ if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
+ goto end;
+ }
+
+ /* reset state for a new frame */
+ if ((ret = inflateInit(&s->zstream)) != Z_OK) {
+ av_log(avctx, AV_LOG_ERROR, "inflateInit returned error %d\n", ret);
+ ret = AVERROR_EXTERNAL;
+ goto end;
+ }
+ s->y = 0;
+ s->state &= ~(PNG_IDAT | PNG_ALLIMAGE);
+ bytestream2_init(&s->gb, avpkt->data, avpkt->size);
+ if ((ret = decode_frame_common(avctx, s, p, avpkt)) < 0)
+ goto end;
+
+ if (!(s->state & PNG_ALLIMAGE))
+ av_log(avctx, AV_LOG_WARNING, "Frame did not contain a complete image\n");
+ if (!(s->state & (PNG_ALLIMAGE|PNG_IDAT))) {
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+ if ((ret = av_frame_ref(data, s->picture.f)) < 0)
+ goto end;
+
+ *got_frame = 1;
+ ret = bytestream2_tell(&s->gb);
+
+end:
+ inflateEnd(&s->zstream);
+ return ret;
+}
+#endif
static int update_thread_context(AVCodecContext *dst, const AVCodecContext *src)
{
@@ -1000,6 +1118,23 @@ static av_cold int png_dec_end(AVCodecContext *avctx)
return 0;
}
+#if CONFIG_APNG_DECODER
+AVCodec ff_apng_decoder = {
+ .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(PNGDecContext),
+ .init = png_dec_init,
+ .close = png_dec_end,
+ .decode = decode_frame_apng,
+ .init_thread_copy = ONLY_IF_THREADS_ENABLED(png_dec_init),
+ .update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
+ .capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
+};
+#endif
+
+#if CONFIG_PNG_DECODER
AVCodec ff_png_decoder = {
.name = "png",
.long_name = NULL_IF_CONFIG_SMALL("PNG (Portable Network Graphics) image"),
@@ -1013,3 +1148,4 @@ AVCodec ff_png_decoder = {
.update_thread_context = ONLY_IF_THREADS_ENABLED(update_thread_context),
.capabilities = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
};
+#endif
--
2.2.0.rc2.23.gca0107e
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