[FFmpeg-cvslog] libavcodec/libvpx: Add VPx alpha decode support
Vignesh Venkatasubramanian
git at videolan.org
Wed Jul 20 07:04:00 EEST 2016
ffmpeg | branch: master | Vignesh Venkatasubramanian <vigneshv-at-google.com at ffmpeg.org> | Thu Jul 14 12:15:57 2016 -0700| [134fe28981cd94206cf4dcfd468ccc1b76391980] | committer: James Zern
libavcodec/libvpx: Add VPx alpha decode support
VPx (VP8/VP9) alpha encoding has been part of FFmpeg. Now, add the
ability to decode such files with alpha channel.
Signed-off-by: Vignesh Venkatasubramanian <vigneshv at google.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=134fe28981cd94206cf4dcfd468ccc1b76391980
---
libavcodec/libvpxdec.c | 107 +++++++++++++++++++++++++++++++++++++++---------
1 file changed, 87 insertions(+), 20 deletions(-)
diff --git a/libavcodec/libvpxdec.c b/libavcodec/libvpxdec.c
index adbc6d0..f7acc39 100644
--- a/libavcodec/libvpxdec.c
+++ b/libavcodec/libvpxdec.c
@@ -29,6 +29,7 @@
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
+#include "libavutil/intreadwrite.h"
#include "avcodec.h"
#include "internal.h"
#include "libvpx.h"
@@ -36,10 +37,13 @@
typedef struct VP8DecoderContext {
struct vpx_codec_ctx decoder;
+ struct vpx_codec_ctx decoder_alpha;
+ int has_alpha_channel;
} VP8Context;
static av_cold int vpx_init(AVCodecContext *avctx,
- const struct vpx_codec_iface *iface)
+ const struct vpx_codec_iface *iface,
+ int is_alpha_decoder)
{
VP8Context *ctx = avctx->priv_data;
struct vpx_codec_dec_cfg deccfg = {
@@ -50,7 +54,9 @@ static av_cold int vpx_init(AVCodecContext *avctx,
av_log(avctx, AV_LOG_INFO, "%s\n", vpx_codec_version_str());
av_log(avctx, AV_LOG_VERBOSE, "%s\n", vpx_codec_build_config());
- if (vpx_codec_dec_init(&ctx->decoder, iface, &deccfg, 0) != VPX_CODEC_OK) {
+ if (vpx_codec_dec_init(
+ is_alpha_decoder ? &ctx->decoder_alpha : &ctx->decoder,
+ iface, &deccfg, 0) != VPX_CODEC_OK) {
const char *error = vpx_codec_error(&ctx->decoder);
av_log(avctx, AV_LOG_ERROR, "Failed to initialize decoder: %s\n",
error);
@@ -61,7 +67,8 @@ static av_cold int vpx_init(AVCodecContext *avctx,
}
// returns 0 on success, AVERROR_INVALIDDATA otherwise
-static int set_pix_fmt(AVCodecContext *avctx, struct vpx_image *img)
+static int set_pix_fmt(AVCodecContext *avctx, struct vpx_image *img,
+ int has_alpha_channel)
{
#if VPX_IMAGE_ABI_VERSION >= 3
static const enum AVColorSpace colorspaces[8] = {
@@ -82,7 +89,8 @@ static int set_pix_fmt(AVCodecContext *avctx, struct vpx_image *img)
case VPX_IMG_FMT_I420:
if (avctx->codec_id == AV_CODEC_ID_VP9)
avctx->profile = FF_PROFILE_VP9_0;
- avctx->pix_fmt = AV_PIX_FMT_YUV420P;
+ avctx->pix_fmt =
+ has_alpha_channel ? AV_PIX_FMT_YUVA420P : AV_PIX_FMT_YUV420P;
return 0;
#if CONFIG_LIBVPX_VP9_DECODER
case VPX_IMG_FMT_I422:
@@ -168,29 +176,75 @@ static int set_pix_fmt(AVCodecContext *avctx, struct vpx_image *img)
}
}
+static int decode_frame(AVCodecContext *avctx, vpx_codec_ctx_t *decoder,
+ uint8_t *data, uint32_t data_sz)
+{
+ if (vpx_codec_decode(decoder, data, data_sz, NULL, 0) != VPX_CODEC_OK) {
+ const char *error = vpx_codec_error(decoder);
+ const char *detail = vpx_codec_error_detail(decoder);
+
+ av_log(avctx, AV_LOG_ERROR, "Failed to decode frame: %s\n", error);
+ if (detail) {
+ av_log(avctx, AV_LOG_ERROR, " Additional information: %s\n",
+ detail);
+ }
+ return AVERROR_INVALIDDATA;
+ }
+ return 0;
+}
+
static int vp8_decode(AVCodecContext *avctx,
void *data, int *got_frame, AVPacket *avpkt)
{
VP8Context *ctx = avctx->priv_data;
AVFrame *picture = data;
const void *iter = NULL;
- struct vpx_image *img;
+ const void *iter_alpha = NULL;
+ struct vpx_image *img, *img_alpha;
int ret;
+ uint8_t *side_data = NULL;
+ int side_data_size = 0;
- if (vpx_codec_decode(&ctx->decoder, avpkt->data, avpkt->size, NULL, 0) !=
- VPX_CODEC_OK) {
- const char *error = vpx_codec_error(&ctx->decoder);
- const char *detail = vpx_codec_error_detail(&ctx->decoder);
+ ret = decode_frame(avctx, &ctx->decoder, avpkt->data, avpkt->size);
+ if (ret)
+ return ret;
- av_log(avctx, AV_LOG_ERROR, "Failed to decode frame: %s\n", error);
- if (detail)
- av_log(avctx, AV_LOG_ERROR, " Additional information: %s\n",
- detail);
- return AVERROR_INVALIDDATA;
+ side_data = av_packet_get_side_data(avpkt,
+ AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
+ &side_data_size);
+ if (side_data_size > 1) {
+ const uint64_t additional_id = AV_RB64(side_data);
+ side_data += 8;
+ side_data_size -= 8;
+ if (additional_id == 1) { // 1 stands for alpha channel data.
+ if (!ctx->has_alpha_channel) {
+ ctx->has_alpha_channel = 1;
+ ret = vpx_init(avctx,
+#if CONFIG_LIBVPX_VP8_DECODER && CONFIG_LIBVPX_VP9_DECODER
+ (avctx->codec_id == AV_CODEC_ID_VP8) ?
+ &vpx_codec_vp8_dx_algo : &vpx_codec_vp9_dx_algo,
+#elif CONFIG_LIBVPX_VP8_DECODER
+ &vpx_codec_vp8_dx_algo,
+#else
+ &vpx_codec_vp9_dx_algo,
+#endif
+ 1);
+ if (ret)
+ return ret;
+ }
+ ret = decode_frame(avctx, &ctx->decoder_alpha, side_data,
+ side_data_size);
+ if (ret)
+ return ret;
+ }
}
- if ((img = vpx_codec_get_frame(&ctx->decoder, &iter))) {
- if ((ret = set_pix_fmt(avctx, img)) < 0) {
+ if ((img = vpx_codec_get_frame(&ctx->decoder, &iter)) &&
+ (!ctx->has_alpha_channel ||
+ (img_alpha = vpx_codec_get_frame(&ctx->decoder_alpha, &iter_alpha)))) {
+ uint8_t *planes[4];
+ int linesizes[4];
+ if ((ret = set_pix_fmt(avctx, img, ctx->has_alpha_channel)) < 0) {
#ifdef VPX_IMG_FMT_HIGHBITDEPTH
av_log(avctx, AV_LOG_ERROR, "Unsupported output colorspace (%d) / bit_depth (%d)\n",
img->fmt, img->bit_depth);
@@ -210,8 +264,19 @@ static int vp8_decode(AVCodecContext *avctx,
}
if ((ret = ff_get_buffer(avctx, picture, 0)) < 0)
return ret;
- av_image_copy(picture->data, picture->linesize, (const uint8_t **)img->planes,
- img->stride, avctx->pix_fmt, img->d_w, img->d_h);
+
+ planes[0] = img->planes[VPX_PLANE_Y];
+ planes[1] = img->planes[VPX_PLANE_U];
+ planes[2] = img->planes[VPX_PLANE_V];
+ planes[3] =
+ ctx->has_alpha_channel ? img_alpha->planes[VPX_PLANE_Y] : NULL;
+ linesizes[0] = img->stride[VPX_PLANE_Y];
+ linesizes[1] = img->stride[VPX_PLANE_U];
+ linesizes[2] = img->stride[VPX_PLANE_V];
+ linesizes[3] =
+ ctx->has_alpha_channel ? img_alpha->stride[VPX_PLANE_Y] : 0;
+ av_image_copy(picture->data, picture->linesize, (const uint8_t**)planes,
+ linesizes, avctx->pix_fmt, img->d_w, img->d_h);
*got_frame = 1;
}
return avpkt->size;
@@ -221,13 +286,15 @@ static av_cold int vp8_free(AVCodecContext *avctx)
{
VP8Context *ctx = avctx->priv_data;
vpx_codec_destroy(&ctx->decoder);
+ if (ctx->has_alpha_channel)
+ vpx_codec_destroy(&ctx->decoder_alpha);
return 0;
}
#if CONFIG_LIBVPX_VP8_DECODER
static av_cold int vp8_init(AVCodecContext *avctx)
{
- return vpx_init(avctx, &vpx_codec_vp8_dx_algo);
+ return vpx_init(avctx, &vpx_codec_vp8_dx_algo, 0);
}
AVCodec ff_libvpx_vp8_decoder = {
@@ -246,7 +313,7 @@ AVCodec ff_libvpx_vp8_decoder = {
#if CONFIG_LIBVPX_VP9_DECODER
static av_cold int vp9_init(AVCodecContext *avctx)
{
- return vpx_init(avctx, &vpx_codec_vp9_dx_algo);
+ return vpx_init(avctx, &vpx_codec_vp9_dx_algo, 0);
}
AVCodec ff_libvpx_vp9_decoder = {
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