Add a libwebp encoder

1 files changed, 287 insertions, 0 deletions

diff --git a/libavcodec/libwebpenc.c b/libavcodec/libwebpenc.c
new file mode 100644
index 0000000..74e73dc
--- /dev/null
+++ b/libavcodec/libwebpenc.c
@@ -0,0 +1,287 @@
+/*
+ * WebP encoding support via libwebp
+ * Copyright (c) 2013 Justin Ruggles <justin.ruggles@gmail.com>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * WebP encoder using libwebp
+ */
+
+#include <webp/encode.h>
+
+#include "libavutil/common.h"
+#include "libavutil/frame.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/opt.h"
+#include "avcodec.h"
+#include "internal.h"
+
+typedef struct LibWebPContext {
+    AVClass *class;         // class for AVOptions
+    float quality;          // lossy quality 0 - 100
+    int lossless;           // use lossless encoding
+    int preset;             // configuration preset
+    int chroma_warning;     // chroma linesize mismatch warning has been printed
+    int conversion_warning; // pixel format conversion warning has been printed
+    WebPConfig config;      // libwebp configuration
+} LibWebPContext;
+
+static int libwebp_error_to_averror(int err)
+{
+    switch (err) {
+    case VP8_ENC_ERROR_OUT_OF_MEMORY:
+    case VP8_ENC_ERROR_BITSTREAM_OUT_OF_MEMORY:
+        return AVERROR(ENOMEM);
+    case VP8_ENC_ERROR_NULL_PARAMETER:
+    case VP8_ENC_ERROR_INVALID_CONFIGURATION:
+    case VP8_ENC_ERROR_BAD_DIMENSION:
+        return AVERROR(EINVAL);
+    }
+    return AVERROR_UNKNOWN;
+}
+
+static av_cold int libwebp_encode_init(AVCodecContext *avctx)
+{
+    LibWebPContext *s = avctx->priv_data;
+    int ret;
+
+    if (avctx->global_quality < 0)
+        avctx->global_quality = 75 * FF_QP2LAMBDA;
+    s->quality = av_clipf(avctx->global_quality / (float)FF_QP2LAMBDA,
+                          0.0f, 100.0f);
+
+    if (avctx->compression_level < 0 || avctx->compression_level > 6) {
+        av_log(avctx, AV_LOG_WARNING, "invalid compression level: %d\n",
+               avctx->compression_level);
+        avctx->compression_level = av_clip(avctx->compression_level, 0, 6);
+    }
+
+    if (s->preset >= WEBP_PRESET_DEFAULT) {
+        ret = WebPConfigPreset(&s->config, s->preset, s->quality);
+        if (!ret)
+            return AVERROR_UNKNOWN;
+        s->lossless              = s->config.lossless;
+        s->quality               = s->config.quality;
+        avctx->compression_level = s->config.method;
+    } else {
+        ret = WebPConfigInit(&s->config);
+        if (!ret)
+            return AVERROR_UNKNOWN;
+
+        s->config.lossless = s->lossless;
+        s->config.quality  = s->quality;
+        s->config.method   = avctx->compression_level;
+
+        ret = WebPValidateConfig(&s->config);
+        if (!ret)
+            return AVERROR(EINVAL);
+    }
+
+    av_log(avctx, AV_LOG_DEBUG, "%s - quality=%.1f method=%d\n",
+           s->lossless ? "Lossless" : "Lossy", s->quality,
+           avctx->compression_level);
+
+    return 0;
+}
+
+static int libwebp_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
+                                const AVFrame *frame, int *got_packet)
+{
+    LibWebPContext *s  = avctx->priv_data;
+    AVFrame *alt_frame = NULL;
+    WebPPicture *pic = NULL;
+    WebPMemoryWriter mw = { 0 };
+    int ret;
+
+    if (avctx->width > WEBP_MAX_DIMENSION || avctx->height > WEBP_MAX_DIMENSION) {
+        av_log(avctx, AV_LOG_ERROR, "Picture size is too large. Max is %dx%d.\n",
+               WEBP_MAX_DIMENSION, WEBP_MAX_DIMENSION);
+        return AVERROR(EINVAL);
+    }
+
+    pic = av_malloc(sizeof(*pic));
+    if (!pic)
+        return AVERROR(ENOMEM);
+
+    ret = WebPPictureInit(pic);
+    if (!ret) {
+        ret = AVERROR_UNKNOWN;
+        goto end;
+    }
+    pic->width  = avctx->width;
+    pic->height = avctx->height;
+
+    if (avctx->pix_fmt == AV_PIX_FMT_RGB32) {
+        if (!s->lossless) {
+            /* libwebp will automatically convert RGB input to YUV when
+               encoding lossy. */
+            if (!s->conversion_warning) {
+                av_log(avctx, AV_LOG_WARNING,
+                       "Using libwebp for RGB-to-YUV conversion. You may want "
+                       "to consider passing in YUV instead for lossy "
+                       "encoding.\n");
+                s->conversion_warning = 1;
+            }
+        }
+        pic->use_argb    = 1;
+        pic->argb        = (uint32_t *)frame->data[0];
+        pic->argb_stride = frame->linesize[0] / 4;
+    } else {
+        if (frame->linesize[1] != frame->linesize[2]) {
+            if (!s->chroma_warning) {
+                av_log(avctx, AV_LOG_WARNING,
+                       "Copying frame due to differing chroma linesizes.\n");
+                s->chroma_warning = 1;
+            }
+            alt_frame = av_frame_alloc();
+            if (!alt_frame) {
+                ret = AVERROR(ENOMEM);
+                goto end;
+            }
+            alt_frame->width  = frame->width;
+            alt_frame->height = frame->height;
+            alt_frame->format = frame->format;
+            ret = av_frame_get_buffer(alt_frame, 32);
+            if (ret < 0)
+                goto end;
+            av_image_copy(alt_frame->data, alt_frame->linesize,
+                          frame->data, frame->linesize,
+                          avctx->pix_fmt, frame->width, frame->height);
+            frame = alt_frame;
+        }
+        pic->use_argb  = 0;
+        pic->y         = frame->data[0];
+        pic->u         = frame->data[1];
+        pic->v         = frame->data[2];
+        pic->y_stride  = frame->linesize[0];
+        pic->uv_stride = frame->linesize[1];
+        if (avctx->pix_fmt == AV_PIX_FMT_YUVA420P) {
+            pic->colorspace = WEBP_YUV420A;
+            pic->a          = frame->data[3];
+            pic->a_stride   = frame->linesize[3];
+        } else {
+            pic->colorspace = WEBP_YUV420;
+        }
+
+        if (s->lossless) {
+            /* We do not have a way to automatically prioritize RGB over YUV
+               in automatic pixel format conversion based on whether we're
+               encoding lossless or lossy, so we do conversion with libwebp as
+               a convenience. */
+            if (!s->conversion_warning) {
+                av_log(avctx, AV_LOG_WARNING,
+                       "Using libwebp for YUV-to-RGB conversion. You may want "
+                       "to consider passing in RGB instead for lossless "
+                       "encoding.\n");
+                s->conversion_warning = 1;
+            }
+
+#if (WEBP_ENCODER_ABI_VERSION <= 0x201)
+            /* libwebp should do the conversion automatically, but there is a
+               bug that causes it to return an error instead, so a work-around
+               is required.
+               See https://code.google.com/p/webp/issues/detail?id=178 */
+            pic->memory_ = (void*)1;  /* something non-null */
+            ret = WebPPictureYUVAToARGB(pic);
+            if (!ret) {
+                av_log(avctx, AV_LOG_ERROR,
+                       "WebPPictureYUVAToARGB() failed with error: %d\n",
+                       pic->error_code);
+                ret = libwebp_error_to_averror(pic->error_code);
+                goto end;
+            }
+            pic->memory_ = NULL;  /* restore pointer */
+#endif
+        }
+    }
+
+    WebPMemoryWriterInit(&mw);
+    pic->custom_ptr = &mw;
+    pic->writer     = WebPMemoryWrite;
+
+    ret = WebPEncode(&s->config, pic);
+    if (!ret) {
+        av_log(avctx, AV_LOG_ERROR, "WebPEncode() failed with error: %d\n",
+               pic->error_code);
+        ret = libwebp_error_to_averror(pic->error_code);
+        goto end;
+    }
+
+    ret = ff_alloc_packet(pkt, mw.size);
+    if (ret < 0)
+        goto end;
+    memcpy(pkt->data, mw.mem, mw.size);
+
+    pkt->flags |= AV_PKT_FLAG_KEY;
+    *got_packet = 1;
+
+end:
+    free(mw.mem); /* must use free() according to libwebp documentation */
+    WebPPictureFree(pic);
+    av_freep(&pic);
+    av_frame_free(&alt_frame);
+
+    return ret;
+}
+
+#define OFFSET(x) offsetof(LibWebPContext, x)
+#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
+static const AVOption options[] = {
+    { "lossless",   "Use lossless mode",       OFFSET(lossless), AV_OPT_TYPE_INT,   { .i64 =  0 },  0, 1,                           VE           },
+    { "preset",     "Configuration preset",    OFFSET(preset),   AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, WEBP_PRESET_TEXT,            VE, "preset" },
+    { "none",       "do not use a preset",                              0, AV_OPT_TYPE_CONST, { .i64 = -1                  }, 0, 0, VE, "preset" },
+    { "default",    "default preset",                                   0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DEFAULT }, 0, 0, VE, "preset" },
+    { "picture",    "digital picture, like portrait, inner shot",       0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PICTURE }, 0, 0, VE, "preset" },
+    { "photo",      "outdoor photograph, with natural lighting",        0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_PHOTO   }, 0, 0, VE, "preset" },
+    { "drawing",    "hand or line drawing, with high-contrast details", 0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_DRAWING }, 0, 0, VE, "preset" },
+    { "icon",       "small-sized colorful images",                      0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_ICON    }, 0, 0, VE, "preset" },
+    { "text",       "text-like",                                        0, AV_OPT_TYPE_CONST, { .i64 = WEBP_PRESET_TEXT    }, 0, 0, VE, "preset" },
+    { NULL },
+};
+
+static const AVClass class = {
+    .class_name = "libwebp",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+static const AVCodecDefault libwebp_defaults[] = {
+    { "compression_level",  "4"  },
+    { "global_quality",     "-1" },
+    { NULL },
+};
+
+AVCodec ff_libwebp_encoder = {
+    .name           = "libwebp",
+    .long_name      = NULL_IF_CONFIG_SMALL("libwebp WebP image"),
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = AV_CODEC_ID_WEBP,
+    .priv_data_size = sizeof(LibWebPContext),
+    .init           = libwebp_encode_init,
+    .encode2        = libwebp_encode_frame,
+    .pix_fmts       = (const enum AVPixelFormat[]) {
+        AV_PIX_FMT_RGB32,
+        AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P,
+        AV_PIX_FMT_NONE
+    },
+    .priv_class     = &class,
+    .defaults       = libwebp_defaults,
+};