avcodec/hevc_parser: move slice header parsing to its own function

Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Reviewed-by: Aaron Levinson <alevinsn@aracnet.com>
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/hevc_parser.c

@@ -92,77 +92,15 @@ static int hevc_find_frame_end(AVCodecParserContext *s, const uint8_t *buf,
     return END_NOT_FOUND;
 }
 
-/**
- * Parse NAL units of found picture and decode some basic information.
- *
- * @param s parser context.
- * @param avctx codec context.
- * @param buf buffer with field/frame data.
- * @param buf_size size of the buffer.
- */
-static inline int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
-                           int buf_size, AVCodecContext *avctx)
+static int hevc_parse_slice_header(AVCodecParserContext *s, H2645NAL *nal,
+                                   AVCodecContext *avctx)
 {
     HEVCParserContext *ctx = s->priv_data;
-    SliceHeader        *sh = &ctx->sh;
     HEVCParamSets *ps = &ctx->ps;
     HEVCSEIContext *sei = &ctx->sei;
-    int is_global = buf == avctx->extradata;
-    int i, ret;
-
-    /* set some sane default values */
-    s->pict_type         = AV_PICTURE_TYPE_I;
-    s->key_frame         = 0;
-    s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
-
-    ff_hevc_reset_sei(sei);
-
-    ret = ff_h2645_packet_split(&ctx->pkt, buf, buf_size, avctx, 0, 0,
-                                AV_CODEC_ID_HEVC, 1);
-    if (ret < 0)
-        return ret;
-
-    for (i = 0; i < ctx->pkt.nb_nals; i++) {
-        H2645NAL *nal = &ctx->pkt.nals[i];
+    SliceHeader *sh = &ctx->sh;
     GetBitContext *gb = &nal->gb;
-        int num = 0, den = 0;
-
-
-        switch (nal->type) {
-        case HEVC_NAL_VPS:
-            ff_hevc_decode_nal_vps(gb, avctx, ps);
-            break;
-        case HEVC_NAL_SPS:
-            ff_hevc_decode_nal_sps(gb, avctx, ps, 1);
-            break;
-        case HEVC_NAL_PPS:
-            ff_hevc_decode_nal_pps(gb, avctx, ps);
-            break;
-        case HEVC_NAL_SEI_PREFIX:
-        case HEVC_NAL_SEI_SUFFIX:
-            ff_hevc_decode_nal_sei(gb, avctx, sei, ps, nal->type);
-            break;
-        case HEVC_NAL_TRAIL_N:
-        case HEVC_NAL_TRAIL_R:
-        case HEVC_NAL_TSA_N:
-        case HEVC_NAL_TSA_R:
-        case HEVC_NAL_STSA_N:
-        case HEVC_NAL_STSA_R:
-        case HEVC_NAL_RADL_N:
-        case HEVC_NAL_RADL_R:
-        case HEVC_NAL_RASL_N:
-        case HEVC_NAL_RASL_R:
-        case HEVC_NAL_BLA_W_LP:
-        case HEVC_NAL_BLA_W_RADL:
-        case HEVC_NAL_BLA_N_LP:
-        case HEVC_NAL_IDR_W_RADL:
-        case HEVC_NAL_IDR_N_LP:
-        case HEVC_NAL_CRA_NUT:
-
-            if (is_global) {
-                av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit: %d\n", nal->type);
-                return AVERROR_INVALIDDATA;
-            }
+    int i, num = 0, den = 0;
 
     sh->first_slice_in_pic_flag = get_bits1(gb);
     s->picture_structure = sei->picture_timing.picture_struct;
@@ -229,7 +167,7 @@ static inline int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
         sh->dependent_slice_segment_flag = 0;
 
     if (sh->dependent_slice_segment_flag)
-                break;
+        return 0; /* break; */
 
     for (i = 0; i < ps->pps->num_extra_slice_header_bits; i++)
         skip_bits(gb, 1); // slice_reserved_undetermined_flag[]
@@ -267,7 +205,82 @@ static inline int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
         nal->type != HEVC_NAL_RASL_R)
         ctx->pocTid0 = ctx->poc;
 
-            return 0; /* no need to evaluate the rest */
+    return 1; /* no need to evaluate the rest */
+}
+
+/**
+ * Parse NAL units of found picture and decode some basic information.
+ *
+ * @param s parser context.
+ * @param avctx codec context.
+ * @param buf buffer with field/frame data.
+ * @param buf_size size of the buffer.
+ */
+static inline int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
+                           int buf_size, AVCodecContext *avctx)
+{
+    HEVCParserContext *ctx = s->priv_data;
+    HEVCParamSets *ps = &ctx->ps;
+    HEVCSEIContext *sei = &ctx->sei;
+    int is_global = buf == avctx->extradata;
+    int i, ret;
+
+    /* set some sane default values */
+    s->pict_type         = AV_PICTURE_TYPE_I;
+    s->key_frame         = 0;
+    s->picture_structure = AV_PICTURE_STRUCTURE_UNKNOWN;
+
+    ff_hevc_reset_sei(sei);
+
+    ret = ff_h2645_packet_split(&ctx->pkt, buf, buf_size, avctx, 0, 0,
+                                AV_CODEC_ID_HEVC, 1);
+    if (ret < 0)
+        return ret;
+
+    for (i = 0; i < ctx->pkt.nb_nals; i++) {
+        H2645NAL *nal = &ctx->pkt.nals[i];
+        GetBitContext *gb = &nal->gb;
+
+        switch (nal->type) {
+        case HEVC_NAL_VPS:
+            ff_hevc_decode_nal_vps(gb, avctx, ps);
+            break;
+        case HEVC_NAL_SPS:
+            ff_hevc_decode_nal_sps(gb, avctx, ps, 1);
+            break;
+        case HEVC_NAL_PPS:
+            ff_hevc_decode_nal_pps(gb, avctx, ps);
+            break;
+        case HEVC_NAL_SEI_PREFIX:
+        case HEVC_NAL_SEI_SUFFIX:
+            ff_hevc_decode_nal_sei(gb, avctx, sei, ps, nal->type);
+            break;
+        case HEVC_NAL_TRAIL_N:
+        case HEVC_NAL_TRAIL_R:
+        case HEVC_NAL_TSA_N:
+        case HEVC_NAL_TSA_R:
+        case HEVC_NAL_STSA_N:
+        case HEVC_NAL_STSA_R:
+        case HEVC_NAL_RADL_N:
+        case HEVC_NAL_RADL_R:
+        case HEVC_NAL_RASL_N:
+        case HEVC_NAL_RASL_R:
+        case HEVC_NAL_BLA_W_LP:
+        case HEVC_NAL_BLA_W_RADL:
+        case HEVC_NAL_BLA_N_LP:
+        case HEVC_NAL_IDR_W_RADL:
+        case HEVC_NAL_IDR_N_LP:
+        case HEVC_NAL_CRA_NUT:
+
+            if (is_global) {
+                av_log(avctx, AV_LOG_ERROR, "Invalid NAL unit: %d\n", nal->type);
+                return AVERROR_INVALIDDATA;
+            }
+
+            ret = hevc_parse_slice_header(s, nal, avctx);
+            if (ret)
+                return ret;
+            break;
         }
     }
     /* didn't find a picture! */