From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 118F940EDB for ; Sat, 12 Mar 2022 12:09:13 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id CAA2668B1DF; Sat, 12 Mar 2022 14:09:10 +0200 (EET) Received: from haasn.dev (haasn.dev [78.46.187.166]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id C494868A958 for ; Sat, 12 Mar 2022 14:09:04 +0200 (EET) Received: from haasn.dev (unknown [10.30.0.2]) by haasn.dev (Postfix) with ESMTP id 767954701D; Sat, 12 Mar 2022 13:09:04 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=haasn.xyz; s=mail; t=1647086944; bh=iJkicLOM05isaSFvQR3tLPc+tnp5xnuLv8WIZrEwM8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IAMVvWAqIszF+V/0JweAxHTHei662kFgx1t7R8I8vNz9l7GokjOOQGcfaT3TsAKaS Vpnv8cYJOSZSga9AuIHGxIl2vmku/9a6DGysngRt+6ry8ye1k3m6PpEVVVmYiqjzZ0 uxAYyYHO/WTOPZlrrHtNKUVESxCT9BCsStoja4sI= From: Niklas Haas To: ffmpeg-devel@ffmpeg.org Date: Sat, 12 Mar 2022 13:04:29 +0100 Message-Id: <20220312120428.103248-1-ffmpeg@haasn.xyz> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220312121047.GB102875@haasn.xyz> References: <20220312121047.GB102875@haasn.xyz> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH v3] avcodec/pngenc: support writing iCCP chunks X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Cc: Niklas Haas Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: From: Niklas Haas encode_zbuf is mostly a mirror image of decode_zbuf. Other than that, the code is pretty straightforward. Special care needs to be taken to avoid writing more than 79 characters of the profile description (the maximum supported). To write the (dynamically sized) deflate-encoded data, we allocate extra space in the packet and use that directly as a scratch buffer. Modify png_write_chunk slightly to allow pre-writing the chunk contents like this. This implementation does unfortunately require initializing the deflate instance twice, but deflateBound() is not redundant with deflate() so we're not throwing away any significant work. Also add a FATE transcode test to ensure that the ICC profile gets encoded correctly. --- Changes in v3: - rewrite to write the chunk in-place (inside the packet buffer) Actually, I implemented an AVBPrint-less version that I think I'm happier with overall. The extent of the "crimes" needed to support writing chunks in-place was a single `if` in png_write_chunk and hard-coding an 8 byte start offset. I like this the most, since it doesn't require dynamic allocation _at all_. It also ends up producing a 1 byte smaller test file for some reason (not as a result of any obvious bug, but simply because zlib compresses the last few bytes of the stream in a slightly different way, probably as a result of some internal heuristics related to the buffer size - the decoded ICC profile checksum is the same). --- libavcodec/pngenc.c | 93 +++++++++++++++++++++++++++++++++++++++++- tests/fate/image.mak | 3 ++ tests/ref/fate/png-icc | 8 ++++ 3 files changed, 102 insertions(+), 2 deletions(-) create mode 100644 tests/ref/fate/png-icc diff --git a/libavcodec/pngenc.c b/libavcodec/pngenc.c index 3ebcc1e571..e9bbe33adf 100644 --- a/libavcodec/pngenc.c +++ b/libavcodec/pngenc.c @@ -235,7 +235,8 @@ static void png_write_chunk(uint8_t **f, uint32_t tag, bytestream_put_be32(f, av_bswap32(tag)); if (length > 0) { crc = av_crc(crc_table, crc, buf, length); - memcpy(*f, buf, length); + if (*f != buf) + memcpy(*f, buf, length); *f += length; } bytestream_put_be32(f, ~crc); @@ -343,10 +344,88 @@ static int png_get_gama(enum AVColorTransferCharacteristic trc, uint8_t *buf) return 1; } +static size_t zbuf_bound(const uint8_t *data, size_t size) +{ + z_stream zstream; + size_t bound; + + zstream.zalloc = ff_png_zalloc, + zstream.zfree = ff_png_zfree, + zstream.opaque = NULL; + if (deflateInit(&zstream, Z_DEFAULT_COMPRESSION) != Z_OK) + return 0; + + zstream.next_in = data; + zstream.avail_in = size; + bound = deflateBound(&zstream, size); + deflateEnd(&zstream); + return bound; +} + +static int encode_zbuf(uint8_t **buf, const uint8_t *buf_end, + const uint8_t *data, size_t size) +{ + z_stream zstream; + int ret; + + zstream.zalloc = ff_png_zalloc, + zstream.zfree = ff_png_zfree, + zstream.opaque = NULL; + if (deflateInit(&zstream, Z_DEFAULT_COMPRESSION) != Z_OK) + return AVERROR_EXTERNAL; + zstream.next_in = data; + zstream.avail_in = size; + zstream.next_out = *buf; + zstream.avail_out = buf_end - *buf; + ret = deflate(&zstream, Z_FINISH); + deflateEnd(&zstream); + if (ret != Z_STREAM_END) + return AVERROR_EXTERNAL; + + *buf = zstream.next_out; + return 0; +} + +static int png_write_iccp(uint8_t **bytestream, const uint8_t *end, + const AVFrameSideData *side_data) +{ + const AVDictionaryEntry *entry; + const char *name; + uint8_t *start, *buf; + int ret; + + if (!side_data || !side_data->size) + return 0; + + /* write the chunk contents first */ + start = *bytestream + 8; /* make room for iCCP tag + length */ + buf = start; + + /* profile description */ + entry = av_dict_get(side_data->metadata, "name", NULL, 0); + name = (entry && entry->value[0]) ? entry->value : "icc"; + for (int i = 0;; i++) { + char c = (i == 79) ? 0 : name[i]; + bytestream_put_byte(&buf, c); + if (!c) + break; + } + + /* compression method and profile data */ + bytestream_put_byte(&buf, 0); + if ((ret = encode_zbuf(&buf, end, side_data->data, side_data->size))) + return ret; + + /* rewind to the start and write the chunk header/crc */ + png_write_chunk(bytestream, MKTAG('i', 'C', 'C', 'P'), start, buf - start); + return 0; +} + static int encode_headers(AVCodecContext *avctx, const AVFrame *pict) { AVFrameSideData *side_data; PNGEncContext *s = avctx->priv_data; + int ret; /* write png header */ AV_WB32(s->buf, avctx->width); @@ -399,7 +478,14 @@ static int encode_headers(AVCodecContext *avctx, const AVFrame *pict) if (png_get_gama(pict->color_trc, s->buf)) png_write_chunk(&s->bytestream, MKTAG('g', 'A', 'M', 'A'), s->buf, 4); - /* put the palette if needed */ + side_data = av_frame_get_side_data(pict, AV_FRAME_DATA_ICC_PROFILE); + if ((ret = png_write_iccp(&s->bytestream, s->bytestream_end, side_data))) { + av_log(avctx, AV_LOG_WARNING, "Failed writing iCCP chunk: %s\n", + av_err2str(ret)); + return ret; + } + + /* put the palette if needed, must be after colorspace information */ if (s->color_type == PNG_COLOR_TYPE_PALETTE) { int has_alpha, alpha, i; unsigned int v; @@ -526,6 +612,7 @@ static int encode_png(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *pict, int *got_packet) { PNGEncContext *s = avctx->priv_data; + const AVFrameSideData *sd; int ret; int enc_row_size; size_t max_packet_size; @@ -537,6 +624,8 @@ static int encode_png(AVCodecContext *avctx, AVPacket *pkt, enc_row_size + 12 * (((int64_t)enc_row_size + IOBUF_SIZE - 1) / IOBUF_SIZE) // IDAT * ceil(enc_row_size / IOBUF_SIZE) ); + if ((sd = av_frame_get_side_data(pict, AV_FRAME_DATA_ICC_PROFILE))) + max_packet_size += zbuf_bound(sd->data, sd->size); if (max_packet_size > INT_MAX) return AVERROR(ENOMEM); ret = ff_alloc_packet(avctx, pkt, max_packet_size); diff --git a/tests/fate/image.mak b/tests/fate/image.mak index 573d398915..da4f3709e9 100644 --- a/tests/fate/image.mak +++ b/tests/fate/image.mak @@ -385,6 +385,9 @@ FATE_PNG_PROBE += fate-png-side-data fate-png-side-data: CMD = run ffprobe$(PROGSSUF)$(EXESUF) -show_frames \ -i $(TARGET_SAMPLES)/png1/lena-int_rgb24.png +FATE_PNG_PROBE += fate-png-icc +fate-png-icc: CMD = transcode png_pipe $(TARGET_SAMPLES)/png1/lena-int_rgb24.png image2 "-c png" + FATE_PNG-$(call DEMDEC, IMAGE2, PNG) += $(FATE_PNG) FATE_PNG_PROBE-$(call DEMDEC, IMAGE2, PNG) += $(FATE_PNG_PROBE) FATE_IMAGE += $(FATE_PNG-yes) diff --git a/tests/ref/fate/png-icc b/tests/ref/fate/png-icc new file mode 100644 index 0000000000..fd92a9f949 --- /dev/null +++ b/tests/ref/fate/png-icc @@ -0,0 +1,8 @@ +a50d37a0e72bddea2fcbba6fb773e2a0 *tests/data/fate/png-icc.image2 +49397 tests/data/fate/png-icc.image2 +#tb 0: 1/25 +#media_type 0: video +#codec_id 0: rawvideo +#dimensions 0: 128x128 +#sar 0: 2835/2835 +0, 0, 0, 1, 49152, 0xe0013dee -- 2.35.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".