Add CDM video decoder.

webkit/media/crypto/ppapi/ffmpeg_cdm_video_decoder.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "webkit/media/crypto/ppapi/ffmpeg_cdm_video_decoder.h"
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "media/base/buffers.h"
+#include "media/base/limits.h"
+#include "media/ffmpeg/ffmpeg_common.h"
+#include "webkit/media/crypto/ppapi/content_decryption_module.h"
+
+// Include FFmpeg header files.
+extern "C" {
+// Temporarily disable possible loss of data warning.
+MSVC_PUSH_DISABLE_WARNING(4244);
+#include <libavcodec/avcodec.h>
+MSVC_POP_WARNING();
+}  // extern "C"
+
+namespace webkit_media {
+
+static const int kDecodeThreads = 1;
+
+static cdm::VideoFormat PixelFormatToCdmVideoFormat(PixelFormat pixel_format) {
+  switch (pixel_format) {
+    case PIX_FMT_YUV420P:
+      return cdm::kYv12;
+    default:
+      DVLOG(1) << "Unsupported PixelFormat: " << pixel_format;
+  }
+  return cdm::kUnknownVideoFormat;
+}
+
+static PixelFormat CdmVideoFormatToPixelFormat(cdm::VideoFormat video_format) {
+  switch (video_format) {
+    case cdm::kYv12:
+    case cdm::kI420:
+      return PIX_FMT_YUV420P;
+    case cdm::kUnknownVideoFormat:
+    default:
+      DVLOG(1) << "Unsupported cdm::VideoFormat: " << video_format;
+  }
+  return PIX_FMT_NONE;
+}
+
+static CodecID CdmVideoCodecToCodecID(
+    cdm::VideoDecoderConfig::VideoCodec video_codec) {
+  if (video_codec == cdm::VideoDecoderConfig::kCodecVP8)

[ddorwin, 2012/10/21 22:10:53]

Why did you change from the switch statement?
(The previous implementation should have had NOTREACHED and return in default
with no return at the end.)

[Tom Finegan, 2012/10/22 02:34:58]

Because it felt like 4 lines of code to read that weren't really doing anything.
This class supports only VP8 anyway, why bother with the switch and default?

[ddorwin, 2012/10/22 05:04:36]

Okay. We should eventually support more codecs and then it might make sense to
go back. Note also that some compiler configs will warn when a switch is
missing.

+    return CODEC_ID_VP8;
+
+  NOTREACHED() << "Unsupported cdm::VideoCodec: " << video_codec;
+  return CODEC_ID_NONE;
+}
+
+static void CdmVideoDecoderConfigToAVCodecContext(
+    const cdm::VideoDecoderConfig& config,
+    AVCodecContext* codec_context) {
+  codec_context->codec_type = AVMEDIA_TYPE_VIDEO;
+  codec_context->codec_id = CdmVideoCodecToCodecID(config.codec);
+  codec_context->profile = FF_PROFILE_UNKNOWN;
+  codec_context->coded_width = config.coded_size.width;
+  codec_context->coded_height = config.coded_size.height;
+  codec_context->pix_fmt = CdmVideoFormatToPixelFormat(config.format);
+
+  if (config.extra_data) {
+    codec_context->extradata_size = config.extra_data_size;
+    codec_context->extradata = reinterpret_cast<uint8_t*>(
+        av_malloc(config.extra_data_size + FF_INPUT_BUFFER_PADDING_SIZE));
+    memcpy(codec_context->extradata, config.extra_data,
+           config.extra_data_size);
+    memset(codec_context->extradata + config.extra_data_size, 0,
+           FF_INPUT_BUFFER_PADDING_SIZE);
+  } else {
+    codec_context->extradata = NULL;
+    codec_context->extradata_size = 0;
+  }
+
+}
+
+static void CopyPlane(const uint8_t* source,
+                      int32_t source_stride,
+                      int32_t target_stride,
+                      int32_t rows,
+                      int32_t copy_bytes_per_row,
+                      uint8_t* target) {
+  DCHECK(source);
+  DCHECK(target);
+  DCHECK_LE(copy_bytes_per_row, source_stride);
+  DCHECK_LE(copy_bytes_per_row, target_stride);
+
+  for (int i = 0; i < rows; ++i) {
+    const int source_offset = i * source_stride;
+    const int target_offset = i * target_stride;
+    memcpy(target + target_offset,
+           source + source_offset,
+           copy_bytes_per_row);
+  }
+}
+
+FFmpegCdmVideoDecoder::FFmpegCdmVideoDecoder(cdm::Allocator* allocator)
+    : codec_context_(NULL),
+      av_frame_(NULL),
+      is_initialized_(false),
+      allocator_(allocator) {
+}
+
+FFmpegCdmVideoDecoder::~FFmpegCdmVideoDecoder() {
+  ReleaseFFmpegResources();
+}
+
+bool FFmpegCdmVideoDecoder::Initialize(const cdm::VideoDecoderConfig& config) {
+  DVLOG(1) << "Initialize()";
+
+  if (!IsValidOutputConfig(config.format, config.coded_size)) {
+    LOG(ERROR) << "Initialize(): invalid video decoder configuration.";
+    return false;
+  }
+
+  if (is_initialized_) {
+    LOG(ERROR) << "Initialize(): Already initialized.";
+    return false;
+  }
+
+  av_register_all();
+
+  // Release existing resources if necessary.
+  ReleaseFFmpegResources();
+
+  // Initialize AVCodecContext structure.
+  codec_context_ = avcodec_alloc_context3(NULL);
+  CdmVideoDecoderConfigToAVCodecContext(config, codec_context_);
+
+  // Enable motion vector search (potentially slow), strong deblocking filter
+  // for damaged macroblocks, and set our error detection sensitivity.
+  codec_context_->error_concealment = FF_EC_GUESS_MVS | FF_EC_DEBLOCK;
+  codec_context_->err_recognition = AV_EF_CAREFUL;
+  codec_context_->thread_count = kDecodeThreads;
+  codec_context_->opaque = this;
+  codec_context_->flags |= CODEC_FLAG_EMU_EDGE;
+  DCHECK_EQ(CODEC_ID_VP8, codec_context_->codec_id);
+
+  AVCodec* codec = avcodec_find_decoder(codec_context_->codec_id);
+  if (!codec) {
+    LOG(ERROR) << "Initialize(): avcodec_find_decoder failed.";
+    return false;
+  }
+
+  int status;
+  if ((status = avcodec_open2(codec_context_, codec, NULL)) < 0) {
+    LOG(ERROR) << "Initialize(): avcodec_open2 failed: " << status;
+    return false;
+  }
+
+  av_frame_ = avcodec_alloc_frame();
+  is_initialized_ = true;
+
+  return true;
+}
+
+void FFmpegCdmVideoDecoder::Deinitialize() {
+  DVLOG(1) << "Deinitialize()";
+  ReleaseFFmpegResources();
+  is_initialized_ = false;
+}
+
+void FFmpegCdmVideoDecoder::Reset() {
+  DVLOG(1) << "Reset()";
+  avcodec_flush_buffers(codec_context_);
+}
+
+// static
+bool FFmpegCdmVideoDecoder::IsValidOutputConfig(cdm::VideoFormat format,
+                                                const cdm::Size& data_size) {
+  return ((format == cdm::kYv12 || format == cdm::kI420) &&
+          (data_size.width % 2) == 0 && (data_size.height % 2) == 0 &&
+          data_size.width > 0 && data_size.height > 0 &&
+          data_size.width <= media::limits::kMaxDimension &&
+          data_size.height <= media::limits::kMaxDimension &&
+          data_size.width * data_size.height <= media::limits::kMaxCanvas);
+}
+
+cdm::Status FFmpegCdmVideoDecoder::DecodeFrame(
+    const uint8_t* compressed_frame,
+    int32_t compressed_frame_size,
+    int64_t timestamp,
+    cdm::VideoFrame* decoded_frame) {
+  DVLOG(1) << "DecodeFrame()";
+  DCHECK(decoded_frame);
+
+  // Create a packet for input data.
+  AVPacket packet;
+  av_init_packet(&packet);
+
+  // The FFmpeg API does not allow us to have const read-only pointers.
+  packet.data = const_cast<uint8_t*>(compressed_frame);
+  packet.size = compressed_frame_size;
+
+  // Let FFmpeg handle presentation timestamp reordering.
+  codec_context_->reordered_opaque = timestamp;
+
+  // Reset frame to default values.
+  avcodec_get_frame_defaults(av_frame_);
+
+  // This is for codecs not using get_buffer to initialize
+  // |av_frame_->reordered_opaque|
+  av_frame_->reordered_opaque = codec_context_->reordered_opaque;
+
+  int frame_decoded = 0;
+  int result = avcodec_decode_video2(codec_context_,
+                                     av_frame_,
+                                     &frame_decoded,
+                                     &packet);
+  // Log the problem when we can't decode a video frame and exit early.
+  if (result < 0) {
+    LOG(ERROR) << "DecodeFrame(): Error decoding video frame with timestamp: "
+               << timestamp << " us, packet size: " << packet.size  << " bytes";
+    return cdm::kDecodeError;
+  }
+
+  // If no frame was produced then signal that more data is required to
+  // produce more frames. This can happen under two circumstances:
+  //   1) Decoder was recently initialized/flushed
+  //   2) End of stream was reached and all internal frames have been output
+  if (frame_decoded == 0) {
+    // There was an input frame, but FFmpeg did not produce an output frame.
+    // More input data is needed to produce output.
+    if (compressed_frame && compressed_frame_size > 0)
+      return cdm::kNeedMoreData;
+
+    // No output frame was produced by FFmpeg, and there was no input data.
+    // The decoder has been flushed.
+    else
+      return cdm::kSuccess;
+  }
+
+  // The decoder is in a bad state and not decoding correctly.
+  // Checking for NULL avoids a crash.
+  if (!av_frame_->data[cdm::VideoFrame::kYPlane] ||
+      !av_frame_->data[cdm::VideoFrame::kUPlane] ||
+      !av_frame_->data[cdm::VideoFrame::kVPlane]) {
+    LOG(ERROR) << "DecodeFrame(): Video frame has invalid frame data.";
+    return cdm::kDecodeError;
+  }
+
+  if (!CopyAvFrameTo(decoded_frame)) {
+    LOG(ERROR) << "DecodeFrame() could not copy video frame to output buffer.";
+    return cdm::kDecodeError;
+  }
+
+  return cdm::kSuccess;
+}
+
+bool FFmpegCdmVideoDecoder::CopyAvFrameTo(cdm::VideoFrame* cdm_video_frame) {
+  DCHECK(cdm_video_frame);
+  DCHECK_EQ(av_frame_->format, PIX_FMT_YUV420P);
+  DCHECK_EQ(av_frame_->width % 2, 0);
+  DCHECK_EQ(av_frame_->height % 2, 0);
+
+  const int y_size = av_frame_->width * av_frame_->height;
+  const int uv_size = y_size / 2;
+  const int space_required = y_size + (uv_size * 2);
+
+  DCHECK(!cdm_video_frame->frame_buffer());
+  cdm_video_frame->set_frame_buffer(allocator_->Allocate(space_required));
+  if (!cdm_video_frame->frame_buffer()) {
+    LOG(ERROR) << "CopyAvFrameTo() cdm::Allocator::Allocate failed.";
+    return false;
+  }
+
+  CopyPlane(av_frame_->base[cdm::VideoFrame::kYPlane],
+            av_frame_->linesize[cdm::VideoFrame::kYPlane],
+            av_frame_->width,
+            av_frame_->height,
+            av_frame_->width,
+            cdm_video_frame->frame_buffer()->data());
+
+  const int uv_stride = av_frame_->width / 2;
+  const int uv_rows = av_frame_->height / 2;
+  CopyPlane(av_frame_->base[cdm::VideoFrame::kUPlane],
+            av_frame_->linesize[cdm::VideoFrame::kUPlane],
+            uv_stride,
+            uv_rows,
+            uv_stride,
+            cdm_video_frame->frame_buffer()->data() + y_size);
+
+  CopyPlane(av_frame_->base[cdm::VideoFrame::kVPlane],
+            av_frame_->linesize[cdm::VideoFrame::kVPlane],
+            uv_stride,
+            uv_rows,
+            uv_stride,
+            cdm_video_frame->frame_buffer()->data() + y_size + uv_size);
+
+  PixelFormat format = static_cast<PixelFormat>(av_frame_->format);
+  cdm_video_frame->set_format(PixelFormatToCdmVideoFormat(format));
+
+  cdm::Size video_frame_size;
+  video_frame_size.width = av_frame_->width;
+  video_frame_size.height = av_frame_->height;
+  cdm_video_frame->set_size(video_frame_size);
+
+  cdm_video_frame->set_plane_offset(cdm::VideoFrame::kYPlane, 0);
+  cdm_video_frame->set_plane_offset(cdm::VideoFrame::kUPlane, y_size);
+  cdm_video_frame->set_plane_offset(cdm::VideoFrame::kVPlane,
+                                    y_size + uv_size);
+
+  cdm_video_frame->set_stride(cdm::VideoFrame::kYPlane, av_frame_->width);
+  cdm_video_frame->set_stride(cdm::VideoFrame::kUPlane, uv_stride);
+  cdm_video_frame->set_stride(cdm::VideoFrame::kVPlane, uv_stride);
+
+  return true;
+}
+
+void FFmpegCdmVideoDecoder::ReleaseFFmpegResources() {
+  DVLOG(1) << "ReleaseFFmpegResources()";
+
+  if (codec_context_) {
+    av_free(codec_context_->extradata);
+    avcodec_close(codec_context_);
+    av_free(codec_context_);
+    codec_context_ = NULL;
+  }
+  if (av_frame_) {
+    av_free(av_frame_);
+    av_frame_ = NULL;
+  }
+}
+
+}  // namespace webkit_media