AMV video encoder.

Authors are Vladimir Voroshilov and Dobrica Pavlinušić based on svn blame/log
For full details of authorship see http://code.google.com/p/amv-codec-tools/

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/allcodecs.c

@@ -71,7 +71,7 @@ void avcodec_register_all(void)
     REGISTER_ENCODER (A64MULTI, a64multi);
     REGISTER_ENCODER (A64MULTI5, a64multi5);
     REGISTER_DECODER (AASC, aasc);
-    REGISTER_DECODER (AMV, amv);
+    REGISTER_ENCDEC  (AMV, amv);
     REGISTER_DECODER (ANM, anm);
     REGISTER_DECODER (ANSI, ansi);
     REGISTER_ENCDEC  (ASV1, asv1);

libavcodec/mjpegenc.c

@@ -200,6 +200,9 @@ void ff_mjpeg_encode_picture_header(MpegEncContext *s)
 
     put_marker(&s->pb, SOI);
 
+    // hack for AMV mjpeg format
+    if(s->avctx->codec_id == CODEC_ID_AMV) return;
+
     jpeg_put_comments(s);
 
     jpeg_table_header(s);
@@ -445,6 +448,28 @@ void ff_mjpeg_encode_mb(MpegEncContext *s, DCTELEM block[6][64])
     s->i_tex_bits += get_bits_diff(s);
 }
 
+// maximum over s->mjpeg_vsample[i]
+#define V_MAX 2
+static int amv_encode_picture(AVCodecContext *avctx,
+                       unsigned char *buf, int buf_size, void *data)
+{
+
+    AVFrame* pic=data;
+    MpegEncContext *s = avctx->priv_data;
+    int i;
+
+    //CODEC_FLAG_EMU_EDGE have to be cleared
+    if(s->avctx->flags & CODEC_FLAG_EMU_EDGE)
+        return -1;
+
+    //picture should be flipped upside-down
+    for(i=0; i < 3; i++) {
+        pic->data[i] += (pic->linesize[i] * (s->mjpeg_vsample[i] * (8 * s->mb_height -((s->height/V_MAX)&7)) - 1 ));
+        pic->linesize[i] *= -1;
+    }
+    return MPV_encode_picture(avctx,buf, buf_size, pic);
+}
+
 AVCodec ff_mjpeg_encoder = {
     .name           = "mjpeg",
     .type           = AVMEDIA_TYPE_VIDEO,
@@ -456,3 +481,14 @@ AVCodec ff_mjpeg_encoder = {
     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, PIX_FMT_NONE},
     .long_name= NULL_IF_CONFIG_SMALL("MJPEG (Motion JPEG)"),
 };
+
+AVCodec ff_amv_encoder = {
+    "amv",
+    AVMEDIA_TYPE_VIDEO,
+    CODEC_ID_AMV,
+    sizeof(MpegEncContext),
+    MPV_encode_init,
+    amv_encode_picture,
+    MPV_encode_end,
+    .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUVJ420P, PIX_FMT_YUVJ422P, -1},
+};

libavcodec/mpegvideo_enc.c

@@ -265,6 +265,7 @@ av_cold int MPV_encode_init(AVCodecContext *avctx)
         }
         break;
     case CODEC_ID_MJPEG:
+    case CODEC_ID_AMV:
         if(avctx->pix_fmt != PIX_FMT_YUVJ420P && avctx->pix_fmt != PIX_FMT_YUVJ422P &&
            ((avctx->pix_fmt != PIX_FMT_YUV420P && avctx->pix_fmt != PIX_FMT_YUV422P) || avctx->strict_std_compliance>FF_COMPLIANCE_UNOFFICIAL)){
             av_log(avctx, AV_LOG_ERROR, "colorspace not supported in jpeg\n");
@@ -530,6 +531,11 @@ av_cold int MPV_encode_init(AVCodecContext *avctx)
     if(s->mpeg_quant || s->codec_id==CODEC_ID_MPEG1VIDEO || s->codec_id==CODEC_ID_MPEG2VIDEO || s->codec_id==CODEC_ID_MJPEG){
         s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
         s->inter_quant_bias= 0;
+    }else if(s->codec_id==CODEC_ID_AMV){
+        s->intra_quant_bias= 0;
+        s->inter_quant_bias= 0;
+        s->fixed_qscale = 1;
+        s->adaptive_quant = 0;
     }else{
         s->intra_quant_bias=0;
         s->inter_quant_bias=-(1<<(QUANT_BIAS_SHIFT-2)); //(a - x/4)/x
@@ -540,6 +546,8 @@ av_cold int MPV_encode_init(AVCodecContext *avctx)
     if(avctx->inter_quant_bias != FF_DEFAULT_QUANT_BIAS)
         s->inter_quant_bias= avctx->inter_quant_bias;
 
+    av_log(avctx, AV_LOG_DEBUG, "intra_quant_bias = %d inter_quant_bias = %d\n",s->intra_quant_bias,s->inter_quant_bias);
+
     avcodec_get_chroma_sub_sample(avctx->pix_fmt, &chroma_h_shift, &chroma_v_shift);
 
     if(avctx->codec_id == CODEC_ID_MPEG4 && s->avctx->time_base.den > (1<<16)-1){
@@ -564,6 +572,7 @@ av_cold int MPV_encode_init(AVCodecContext *avctx)
         break;
     case CODEC_ID_LJPEG:
     case CODEC_ID_MJPEG:
+    case CODEC_ID_AMV:
         s->out_format = FMT_MJPEG;
         s->intra_only = 1; /* force intra only for jpeg */
         if(avctx->codec->id == CODEC_ID_LJPEG && avctx->pix_fmt == PIX_FMT_BGRA){
@@ -1788,6 +1797,7 @@ static av_always_inline void encode_mb_internal(MpegEncContext *s, int motion_x,
             h263_encode_mb(s, s->block, motion_x, motion_y);
         break;
     case CODEC_ID_MJPEG:
+    case CODEC_ID_AMV:
         if (CONFIG_MJPEG_ENCODER)
             ff_mjpeg_encode_mb(s, s->block);
         break;

libavformat/riff.c

@@ -276,6 +276,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { CODEC_ID_G2M,          MKTAG('G', '2', 'M', '2') },
     { CODEC_ID_G2M,          MKTAG('G', '2', 'M', '3') },
     { CODEC_ID_G2M,          MKTAG('G', '2', 'M', '4') },
+    { CODEC_ID_AMV,          MKTAG('A', 'M', 'V', 'F') },
     { CODEC_ID_NONE,         0 }
 };