skia2/experimental/ffmpeg/SkVideoDecoder.cpp
Mike Reed c0ee21feb8 skia helper for encoding video
Change-Id: I36aef5872fc8f5938854ab18b754f3800b9879ad
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215165
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
2019-05-28 20:39:21 +00:00

413 lines
13 KiB
C++

/*
* Copyright 2019 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "experimental/ffmpeg/SkVideoDecoder.h"
#include "include/core/SkColorSpace.h"
#include "include/core/SkImage.h"
#include "include/core/SkYUVAIndex.h"
static SkYUVColorSpace get_yuvspace(AVColorSpace space) {
// this is pretty incomplete -- TODO: look to convert more AVColorSpaces
switch (space) {
case AVCOL_SPC_RGB: return kIdentity_SkYUVColorSpace;
case AVCOL_SPC_BT709: return kRec709_SkYUVColorSpace;
case AVCOL_SPC_SMPTE170M:
case AVCOL_SPC_SMPTE240M:
case AVCOL_SPC_BT470BG: return kRec601_SkYUVColorSpace;
default: break;
}
return kRec709_SkYUVColorSpace;
}
struct av_transfer_characteristics {
// if x < beta delta * x
// else alpha * (x^gama)
float alpha, beta, gamma, delta;
};
// Tables extracted from vf_colorspace.c
const av_transfer_characteristics gTransfer[AVCOL_TRC_NB] = {
[AVCOL_TRC_BT709] = { 1.099, 0.018, 0.45, 4.5 },
[AVCOL_TRC_GAMMA22] = { 1.0, 0.0, 1.0 / 2.2, 0.0 },
[AVCOL_TRC_GAMMA28] = { 1.0, 0.0, 1.0 / 2.8, 0.0 },
[AVCOL_TRC_SMPTE170M] = { 1.099, 0.018, 0.45, 4.5 },
[AVCOL_TRC_SMPTE240M] = { 1.1115, 0.0228, 0.45, 4.0 },
[AVCOL_TRC_IEC61966_2_1] = { 1.055, 0.0031308, 1.0 / 2.4, 12.92 },
[AVCOL_TRC_IEC61966_2_4] = { 1.099, 0.018, 0.45, 4.5 },
[AVCOL_TRC_BT2020_10] = { 1.099, 0.018, 0.45, 4.5 },
[AVCOL_TRC_BT2020_12] = { 1.0993, 0.0181, 0.45, 4.5 },
};
static skcms_TransferFunction compute_transfer(AVColorTransferCharacteristic t) {
const av_transfer_characteristics* av = &gTransfer[AVCOL_TRC_BT709];
if ((unsigned)t < AVCOL_TRC_NB) {
av = &gTransfer[t];
}
if (av->alpha == 0) {
av = &gTransfer[AVCOL_TRC_BT709];
}
skcms_TransferFunction linear_to_encoded = {
av->gamma, sk_float_pow(av->alpha, 1/av->gamma), 0, av->delta, av->beta, 1 - av->alpha, 0,
};
skcms_TransferFunction encoded_to_linear;
bool success = skcms_TransferFunction_invert(&linear_to_encoded, &encoded_to_linear);
SkASSERT(success);
return encoded_to_linear;
}
enum Whitepoint {
WP_D65,
WP_C,
WP_DCI,
WP_E,
WP_NB,
};
const SkPoint gWP[WP_NB] = {
[WP_D65] = { 0.3127f, 0.3290f },
[WP_C] = { 0.3100f, 0.3160f },
[WP_DCI] = { 0.3140f, 0.3510f },
[WP_E] = { 1/3.0f, 1/3.0f },
};
#define ExpandWP(index) gWP[index].fX, gWP[index].fY
const SkColorSpacePrimaries gPrimaries[AVCOL_PRI_NB] = {
[AVCOL_PRI_BT709] = { 0.640f, 0.330f, 0.300f, 0.600f, 0.150f, 0.060f, ExpandWP(WP_D65) },
[AVCOL_PRI_BT470M] = { 0.670f, 0.330f, 0.210f, 0.710f, 0.140f, 0.080f, ExpandWP(WP_C) },
[AVCOL_PRI_BT470BG] = { 0.640f, 0.330f, 0.290f, 0.600f, 0.150f, 0.060f, ExpandWP(WP_D65) },
[AVCOL_PRI_SMPTE170M] = { 0.630f, 0.340f, 0.310f, 0.595f, 0.155f, 0.070f, ExpandWP(WP_D65) },
[AVCOL_PRI_SMPTE240M] = { 0.630f, 0.340f, 0.310f, 0.595f, 0.155f, 0.070f, ExpandWP(WP_D65) },
[AVCOL_PRI_SMPTE428] = { 0.735f, 0.265f, 0.274f, 0.718f, 0.167f, 0.009f, ExpandWP(WP_E) },
[AVCOL_PRI_SMPTE431] = { 0.680f, 0.320f, 0.265f, 0.690f, 0.150f, 0.060f, ExpandWP(WP_DCI) },
[AVCOL_PRI_SMPTE432] = { 0.680f, 0.320f, 0.265f, 0.690f, 0.150f, 0.060f, ExpandWP(WP_D65) },
[AVCOL_PRI_FILM] = { 0.681f, 0.319f, 0.243f, 0.692f, 0.145f, 0.049f, ExpandWP(WP_C) },
[AVCOL_PRI_BT2020] = { 0.708f, 0.292f, 0.170f, 0.797f, 0.131f, 0.046f, ExpandWP(WP_D65) },
[AVCOL_PRI_JEDEC_P22] = { 0.630f, 0.340f, 0.295f, 0.605f, 0.155f, 0.077f, ExpandWP(WP_D65) },
};
sk_sp<SkColorSpace> make_colorspace(AVColorPrimaries primaries,
AVColorTransferCharacteristic transfer) {
if (primaries == AVCOL_PRI_BT709 && transfer == AVCOL_TRC_BT709) {
return SkColorSpace::MakeSRGB();
}
const SkColorSpacePrimaries* p = &gPrimaries[0];
if ((unsigned)primaries < (unsigned)AVCOL_PRI_NB) {
p = &gPrimaries[primaries];
}
skcms_Matrix3x3 matrix;
p->toXYZD50(&matrix);
return SkColorSpace::MakeRGB(compute_transfer(transfer), matrix);
}
// returns true on error (and may dump the particular error message)
static bool check_err(int err, const int silentList[] = nullptr) {
if (err >= 0) {
return false;
}
if (silentList) {
for (; *silentList; ++silentList) {
if (*silentList == err) {
return true; // we still report the error, but we don't printf
}
}
}
char errbuf[128];
const char *errbuf_ptr = errbuf;
if (av_strerror(err, errbuf, sizeof(errbuf)) < 0) {
errbuf_ptr = strerror(AVUNERROR(err));
}
SkDebugf("%s\n", errbuf_ptr);
return true;
}
static int skstream_read_packet(void* ctx, uint8_t* dstBuffer, int dstSize) {
SkStream* stream = (SkStream*)ctx;
int result = (int)stream->read(dstBuffer, dstSize);
if (result == 0) {
result = AVERROR_EOF;
}
return result;
}
static int64_t skstream_seek_packet(void* ctx, int64_t pos, int whence) {
SkStream* stream = (SkStream*)ctx;
switch (whence) {
case SEEK_SET:
break;
case SEEK_CUR:
pos = (int64_t)stream->getPosition() + pos;
break;
case SEEK_END:
pos = (int64_t)stream->getLength() + pos;
break;
default:
return -1;
}
return stream->seek(SkToSizeT(pos)) ? pos : -1;
}
static sk_sp<SkImage> make_yuv_420(GrContext* gr, int w, int h,
uint8_t* const data[], int const strides[],
SkYUVColorSpace yuv_space,
sk_sp<SkColorSpace> cs) {
SkImageInfo info[3];
info[0] = SkImageInfo::Make(w, h, kGray_8_SkColorType, kOpaque_SkAlphaType);
info[1] = SkImageInfo::Make(w/2, h/2, kGray_8_SkColorType, kOpaque_SkAlphaType);
info[2] = SkImageInfo::Make(w/2, h/2, kGray_8_SkColorType, kOpaque_SkAlphaType);
SkPixmap pm[4];
for (int i = 0; i < 3; ++i) {
pm[i] = SkPixmap(info[i], data[i], strides[i]);
}
pm[3].reset(); // no alpha
SkYUVAIndex indices[4];
indices[SkYUVAIndex::kY_Index] = {0, SkColorChannel::kR};
indices[SkYUVAIndex::kU_Index] = {1, SkColorChannel::kR};
indices[SkYUVAIndex::kV_Index] = {2, SkColorChannel::kR};
indices[SkYUVAIndex::kA_Index] = {-1, SkColorChannel::kR};
return SkImage::MakeFromYUVAPixmaps(gr, yuv_space, pm, indices, {w, h},
kTopLeft_GrSurfaceOrigin, false, false, cs);
}
// Init with illegal values, so our first compare will fail, forcing us to compute
// the skcolorspace.
SkVideoDecoder::ConvertedColorSpace::ConvertedColorSpace()
: fPrimaries(AVCOL_PRI_NB), fTransfer(AVCOL_TRC_NB)
{}
void SkVideoDecoder::ConvertedColorSpace::update(AVColorPrimaries primaries,
AVColorTransferCharacteristic transfer) {
if (fPrimaries != primaries || fTransfer != transfer) {
fPrimaries = primaries;
fTransfer = transfer;
fCS = make_colorspace(primaries, transfer);
}
}
double SkVideoDecoder::computeTimeStamp(const AVFrame* frame) const {
AVRational base = fFormatCtx->streams[fStreamIndex]->time_base;
return 1.0 * frame->pts * base.num / base.den;
}
sk_sp<SkImage> SkVideoDecoder::convertFrame(const AVFrame* frame) {
auto yuv_space = get_yuvspace(frame->colorspace);
// we have a 1-entry cache for converting colorspaces
fCSCache.update(frame->color_primaries, frame->color_trc);
// Are these always true? If so, we don't need to check our "cache" on each frame...
SkASSERT(fDecoderCtx->colorspace == frame->colorspace);
SkASSERT(fDecoderCtx->color_primaries == frame->color_primaries);
SkASSERT(fDecoderCtx->color_trc == frame->color_trc);
// Is this always true? If so, we might take advantage of it, knowing up-front if we support
// the format for the whole stream, in which case we might have to ask ffmpeg to convert it
// to something more reasonable (for us)...
SkASSERT(fDecoderCtx->pix_fmt == frame->format);
switch (frame->format) {
case AV_PIX_FMT_YUV420P:
return make_yuv_420(fGr, frame->width, frame->height, frame->data, frame->linesize,
yuv_space, fCSCache.fCS);
break;
default:
SkDebugf("unsupported format (for now)\n");
}
return nullptr;
}
sk_sp<SkImage> SkVideoDecoder::nextImage(double* timeStamp) {
double dummyTimeStampStorage = 0;
if (!timeStamp) {
timeStamp = &dummyTimeStampStorage;
}
if (fFormatCtx == nullptr) {
return nullptr;
}
if (fMode == kProcessing_Mode) {
// We sit in a loop, waiting for the codec to have received enough data (packets)
// to have at least one frame available.
// Treat non-zero return as EOF (or error, which we will decide is also EOF)
while (!av_read_frame(fFormatCtx, &fPacket)) {
if (fPacket.stream_index != fStreamIndex) {
// got a packet for a stream other than our (video) stream, so continue
continue;
}
int ret = avcodec_send_packet(fDecoderCtx, &fPacket);
if (ret == AVERROR(EAGAIN)) {
// may signal that we have plenty already, encouraging us to call receive_frame
// so we don't treat this as an error.
ret = 0;
}
(void)check_err(ret); // we try to continue if there was an error
int silentList[] = {
-35, // Resource temporarily unavailable (need more packets)
0,
};
if (check_err(avcodec_receive_frame(fDecoderCtx, fFrame), silentList)) {
// this may be just "needs more input", so we try to continue
} else {
*timeStamp = this->computeTimeStamp(fFrame);
return this->convertFrame(fFrame);
}
}
fMode = kDraining_Mode;
(void)avcodec_send_packet(fDecoderCtx, nullptr); // signal to start draining
}
if (fMode == kDraining_Mode) {
if (avcodec_receive_frame(fDecoderCtx, fFrame) >= 0) {
*timeStamp = this->computeTimeStamp(fFrame);
return this->convertFrame(fFrame);
}
// else we decide we're done
fMode = kDone_Mode;
}
return nullptr;
}
SkVideoDecoder::SkVideoDecoder(GrContext* gr) : fGr(gr) {}
SkVideoDecoder::~SkVideoDecoder() {
this->reset();
}
void SkVideoDecoder::reset() {
if (fFrame) {
av_frame_free(&fFrame);
fFrame = nullptr;
}
if (fDecoderCtx) {
avcodec_free_context(&fDecoderCtx);
fDecoderCtx = nullptr;
}
if (fFormatCtx) {
avformat_close_input(&fFormatCtx);
fFormatCtx = nullptr;
}
if (fStreamCtx) {
av_freep(&fStreamCtx->buffer);
avio_context_free(&fStreamCtx);
fStreamCtx = nullptr;
}
fStream.reset(nullptr);
fStreamIndex = -1;
fMode = kDone_Mode;
}
bool SkVideoDecoder::loadStream(std::unique_ptr<SkStream> stream) {
this->reset();
if (!stream) {
return false;
}
int bufferSize = 4 * 1024;
uint8_t* buffer = (uint8_t*)av_malloc(bufferSize);
if (!buffer) {
return false;
}
fStream = std::move(stream);
fStreamCtx = avio_alloc_context(buffer, bufferSize, 0, fStream.get(),
skstream_read_packet, nullptr, skstream_seek_packet);
if (!fStreamCtx) {
av_freep(buffer);
this->reset();
return false;
}
fFormatCtx = avformat_alloc_context();
if (!fFormatCtx) {
this->reset();
return false;
}
fFormatCtx->pb = fStreamCtx;
int err = avformat_open_input(&fFormatCtx, nullptr, nullptr, nullptr);
if (err < 0) {
SkDebugf("avformat_open_input failed %d\n", err);
return false;
}
AVCodec* codec;
fStreamIndex = av_find_best_stream(fFormatCtx, AVMEDIA_TYPE_VIDEO, -1, -1, &codec, 0);
if (fStreamIndex < 0) {
SkDebugf("av_find_best_stream failed %d\n", fStreamIndex);
this->reset();
return false;
}
SkASSERT(codec);
fDecoderCtx = avcodec_alloc_context3(codec);
AVStream* strm = fFormatCtx->streams[fStreamIndex];
if ((err = avcodec_parameters_to_context(fDecoderCtx, strm->codecpar)) < 0) {
SkDebugf("avcodec_parameters_to_context failed %d\n", err);
this->reset();
return false;
}
if ((err = avcodec_open2(fDecoderCtx, codec, nullptr)) < 0) {
SkDebugf("avcodec_open2 failed %d\n", err);
this->reset();
return false;
}
fFrame = av_frame_alloc();
SkASSERT(fFrame);
av_init_packet(&fPacket); // is there a "free" call?
fMode = kProcessing_Mode;
return true;
}
SkISize SkVideoDecoder::dimensions() const {
if (!fFormatCtx) {
return {0, 0};
}
AVStream* strm = fFormatCtx->streams[fStreamIndex];
return {strm->codecpar->width, strm->codecpar->height};
}
double SkVideoDecoder::duration() const {
if (!fFormatCtx) {
return 0;
}
AVStream* strm = fFormatCtx->streams[fStreamIndex];
AVRational base = strm->time_base;
return 1.0 * strm->duration * base.num / base.den;
}
bool SkVideoDecoder::rewind() {
auto stream = std::move(fStream);
this->reset();
if (stream) {
stream->rewind();
}
return this->loadStream(std::move(stream));
}