extend decoder to decode mpeg2 frames

Warning: Only compile tested

3 files changed, 50 insertions, 0 deletions

diff --git a/Makefile b/Makefile
index c6adde0..1500077 100644
--- a/Makefile
+++ b/Makefile
@@ -34,6 +34,7 @@ FFMPEG_INC = $(shell pkg-config --cflags-only-I libavcodec)
 # Usually something like -L/path/to/ffmpeg/libavcodec -lavcodec, should work
 # as is if FFmpeg was installed properly and pkg-config is available.
 FFMPEG_LIBS = $(shell pkg-config --libs libavcodec)
+FFMPEG_LIBS += $(shell pkg-config --libs libswscale)
 
 ALSA_INC = $(shell pkg-config --cflags-only-I alsa)
 ALSA_LIBS = $(shell pkg-config --libs alsa)
diff --git a/decoder.c b/decoder.c
index b575d68..8d64850 100644
--- a/decoder.c
+++ b/decoder.c
@@ -74,6 +74,26 @@ cDecoder::cDecoder() : rbuf(50000), ac3dtsDecoder(&rbuf)
         exit(-1);
     }
 
+    rgbFrame = avcodec_alloc_frame();
+    if (!rgbFrame) {
+        esyslog("[dxr3-decoder] failed to alloc rgbFrame");
+        exit(-1);
+    }
+
+    // reserve place for raw data for our rgbFrame
+    uint8_t *buffer;
+    int numBytes;
+    // determine required buffer size and allocate buffer
+    numBytes = avpicture_get_size(PIX_FMT_RGB24, contextVideo->width, contextVideo->height);
+    buffer = (uint8_t *)av_malloc(numBytes * sizeof(uint8_t));
+    if (!buffer) {
+        esyslog("[dxr3-decoder] failed to alloc rgbFrame data");
+        exit(-1);
+    }
+
+    // ssociate the frame with our newly allocated buffer
+    avpicture_fill((AVPicture *)rgbFrame, buffer, PIX_FMT_RGB24, contextVideo->width, contextVideo->height);
+
     lastBitrate = 0xff; // init with an invalid value - see checkMpegAudioHdr;
 }
 
@@ -84,6 +104,11 @@ cDecoder::~cDecoder()
     // close codec, if it is open
     avcodec_close(contextAudio);
     avcodec_close(contextVideo);
+
+    if (rgbFrame) {
+        av_free(rgbFrame->data);
+        av_free(rgbFrame);
+    }
 }
 
 // ==================================
@@ -102,6 +127,27 @@ void cDecoder::Init()
     }
 }
 
+AVFrame *cDecoder::decode(AVPacket *source, uint32_t width, uint32_t height)
+{
+    AVFrame frame;
+    int gotPicture;
+
+    avcodec_decode_video2(contextVideo, &frame, &gotPicture, source);
+
+    if (gotPicture) {
+
+        SwsContext *swsContext = sws_getContext(contextVideo->width, contextVideo->height,
+        contextVideo->pix_fmt, width, height, PIX_FMT_RGB24, SWS_BILINEAR, 0, 0, 0);
+
+        if (swsContext) {
+            sws_scale(swsContext, frame.data, frame.linesize, 0, contextVideo->height, rgbFrame->data, rgbFrame->linesize);
+            return rgbFrame;
+        }
+    }
+
+    return NULL;
+}
+
 void cDecoder::decode(cDxr3PesFrame *frame, iAudio *audio)
 {
     int len, out_size;
diff --git a/decoder.h b/decoder.h
index de2783e..2d04360 100644
--- a/decoder.h
+++ b/decoder.h
@@ -31,6 +31,7 @@
 extern "C" {
 #    include <libavcodec/avcodec.h>
 #    include <libavformat/avformat.h>
+#    include <libswscale/swscale.h>
 }
 
 #include <vdr/ringbuffer.h>
@@ -47,6 +48,7 @@ public:
     cDecoder();
     ~cDecoder();
 
+    AVFrame *decode(AVPacket *source, uint32_t width, uint32_t height);
     void decode(cDxr3PesFrame *frame, iAudio *audio);
     void ac3dts(cDxr3PesFrame *frame, iAudio *audio);
 /*
@@ -68,6 +70,7 @@ private:
     AVCodecContext *contextVideo;
     AVPacket avpkt;
 
+    AVFrame *rgbFrame;
     cRingBufferFrame rbuf;
     cMultichannelAudio ac3dtsDecoder;